- Non-Steroidal Drug Interferences in a Quantitative Multisteroid LC-MS/MS Assay. [Journal Article]Cells. 2023 Jan 15; 12(2)C
- Screening for possible interferences from steroidal compounds other than the target analytes (endogenous or exogenous) is well established in LC-MS/MS assay development for steroid quantification in a routine clinical setting. However, interferences from non-steroidal substances have, hitherto, not been explored. After screening more than 150 pharmaceuticals and their metabolites by analyzing com…
Screening for possible interferences from steroidal compounds other than the target analytes (endogenous or exogenous) is well established in LC-MS/MS assay development for steroid quantification in a routine clinical setting. However, interferences from non-steroidal substances have, hitherto, not been explored. After screening more than 150 pharmaceuticals and their metabolites by analyzing commercial quality control samples from TDM analysis kits (Recipe, Chromsystems) with a multisteroid LC-MS/MS assay (protein precipitation followed by HybridSPE filtration, biphenyl column, methanol-water gradient with NH4F additive), we can report the finding of two newly discovered potential interferences from non-steroidal drugs. Antidepressant paroxetine (PX) was identified as an interference to 17-hydroxyprogesterone (17P), and α-hydroxytriazolam (α-OH-TZM)-a major metabolite of benzodiazepine triazolam (TZM)-was identified as an interference to aldosterone (ALDO). Despite different elemental and structural compositions and nominal masses, the M+1 isotopologues of PX and α-OH-TZM produced overlapping signals in ion traces monitored for the respective analytes (m/z 331 → 109/97 and 361→315/343, respectively). PX and TZM are frequently prescribed drugs, and their therapeutic ranges are far exceeding the reference ranges of 17P or ALDO (µmol vs nmol); therefore, these interferences should be considered clinically relevant. Striving for faster multi-analyte methods with high sample turnover, especially in the field of steroid quantification, can limit assay selectivity and specificity. Therefore, supported by the findings of this study, screening for potential interferences in multi-analyte LC-MS/MS method development should not cover only substances of the same class but also include a set of common drugs.
- Expanded table: Some oral drugs for chronic insomnia. [Journal Article]Med Lett Drugs Ther. 2023 Jan 09; 65(1667):e6-e10.ML
- Physiologically Based Pharmacokinetic Modelling to Identify Physiological and Drug Parameters Driving Pharmacokinetics in Obese Individuals. [Journal Article]Clin Pharmacokinet. 2022 Dec 26 [Online ahead of print]CP
- CONCLUSIONS: Both physiological changes and drug properties impact drug pharmacokinetics in obese subjects. Clearance increases due to enhanced hepatic and renal blood flows. Volume of distribution is higher for all drugs, with differences among drugs depending on their pKa/logP.
- Investigation on toxicological usefulness of synovial fluids, as an alternative matrix: postmortem distribution/redistribution of triazolam and its predominant metabolite α-hydroxytriazolam in human body fluids. [Letter]Forensic Toxicol. 2022 01; 40(1):208-214.FT
- Metabolic disposition of triazolam and clobazam in humanized CYP3A mice with a double knockout background of mouse Cyp2c and Cyp3a genes. [Journal Article]Drug Metab Dispos. 2022 Nov 15 [Online ahead of print]DM
- Knockout (KO) of mouse Cyp3a genes increases the expression of hepatic CYP2C enzymes, which can metabolize triazolam, a typical substrate of human CYP3A. There is still marked formation of 1'-hydroxytriazolam in Cyp3a-KO (3aKO) mice after triazolam dosing. Here, we generated a new model of humanized CYP3A (hCYP3A) mice with a double KO background of Cyp3a and Cyp2c genes (2c3aKO), and we examined…
Knockout (KO) of mouse Cyp3a genes increases the expression of hepatic CYP2C enzymes, which can metabolize triazolam, a typical substrate of human CYP3A. There is still marked formation of 1'-hydroxytriazolam in Cyp3a-KO (3aKO) mice after triazolam dosing. Here, we generated a new model of humanized CYP3A (hCYP3A) mice with a double KO background of Cyp3a and Cyp2c genes (2c3aKO), and we examined the metabolic profiles of triazolam in wild-type (WT), 2c3aKO and hCYP3A/2c3aKO mice in vitro and in vivo In vitro studies using liver microsomes showed that the formation of 1'-hydroxytriazolam in 2c3aKO mice was less than 8% of that in WT mice. The formation rate of 1'-hydroxytriazolam in hCYP3A/2c3aKO mice was 8-fold higher than that in 2c3aKO mice. In vivostudies showed that AUC of 1'-hydroxytriazolam in 2c3aKO mice was less than 3% of that in WT mice. The AUC of 1'-hydroxytriazolam in hCYP3A/2c3aKO mice was 6-fold higher than that in 2c3aKO mice. These results showed that formation of 1'-hydroxytriazolam was significantly decreased in 2c3aKO mice. Metabolic functions of human CYP3A enzymes were distinctly found in hCYP3A mice with the 2c3aKO background. Moreover, hCYP3A/2c3aKO mice treated with clobazam showed human CYP3A-mediated formation of desmethylclobazam and prolonged elimination of desmethylclobazam, which is found in poor metabolizers of CYP2C19. The novel hCYP3A mouse model without mouse Cyp2c and Cyp3a genes (hCYP3A/2c3aKO) is expected to be useful to evaluate human CYP3A-mediated metabolism in vivo Significance Statement Humanized CYP3A (hCYP3A/2c3aKO) mice with a background of double knockout (KO) for mouse Cyp2c and Cyp3a genes were generated. Although CYP2C enzymes played a compensatory role in the metabolism of triazolam to 1'-hydroxytriazolam in the previous hCYP3A/3aKO mice with Cyp2c genes, the novel hCYP3A/2c3aKO mice clearly showed functions of human CYP3A enzymes introduced by chromosome engineering technology.
- Development and validation of the UPLC-MS method for simultaneous determination of six new psychoactive substances. [Journal Article]RSC Adv. 2022 Sep 16; 12(41):26704-26711.RA
- The combined abuse of benzodiazepines and antipsychotics has become a global problem, and to develop a highly sensitive and selective method for monitoring of benzodiazepine hypnotics and antipsychotics is urgently necessary. In this work, we established a rapid method for the simultaneous determination of benzodiazepines (diazepam, alprazolam, triazolam, and estazolam) and antipsychotic drugs (c…
The combined abuse of benzodiazepines and antipsychotics has become a global problem, and to develop a highly sensitive and selective method for monitoring of benzodiazepine hypnotics and antipsychotics is urgently necessary. In this work, we established a rapid method for the simultaneous determination of benzodiazepines (diazepam, alprazolam, triazolam, and estazolam) and antipsychotic drugs (clozapine, and chlorpromazine) based on ultra performance liquid chromatography-mass spectrometry (UPLC-MS). The accuracy, precision, limit of detection (LOD), limit of quantification (LOQ), specificity, matrix effect and carry-over effect were verified in detail. The results of the recovery and repeat experiments proved that the proposed UPLC-MS method possessed very satisfactory accuracy and precision. The LOD and LOQ of the six psychoactive substances were as low as 0.001-0.005 and 0.005-0.01 μg L-1, respectively. The proposed method was employed to analyze urine samples which were pretreated with a protein precipitation process. The potential influences of precipitants on the analysis results were evaluated statistically, and 0.1% formic acid/acetonitrile/water was selected as the optimum precipitation agent. The detection of the targets was free from matrix and carryover effects.
- Phytochemicals That Interfere With Drug Metabolism and Transport, Modifying Plasma Concentration in Humans and Animals. [Review]Dose Response. 2022 Jul-Sep; 20(3):15593258221120485.DR
- Phytochemicals (Pch) present in fruits, vegetables and other foods, are known to inhibit or induce drug metabolism and transport. An exhaustive search was performed in five databases covering from 2000 to 2021. Twenty-one compounds from plants were found to modulate CYP3A and/or P-gp activities and modified the pharmacokinetics and the therapeutic effect of 27 different drugs. Flavonols, flavanon…
Phytochemicals (Pch) present in fruits, vegetables and other foods, are known to inhibit or induce drug metabolism and transport. An exhaustive search was performed in five databases covering from 2000 to 2021. Twenty-one compounds from plants were found to modulate CYP3A and/or P-gp activities and modified the pharmacokinetics and the therapeutic effect of 27 different drugs. Flavonols, flavanones, flavones, stilbenes, diferuloylmethanes, tannins, protoalkaloids, flavans, hyperforin and terpenes, reduce plasma concentration of cyclosporine, simvastatin, celiprolol, midazolam, saquinavir, buspirone, everolimus, nadolol, tamoxifen, alprazolam, verapamil, quazepam, digoxin, fexofenadine, theophylline, indinavir, clopidogrel. Anthocyanins, flavonols, flavones, flavanones, flavonoid glycosides, stilbenes, diferuloylmethanes, catechin, hyperforin, alkaloids, terpenes, tannins and protoalkaloids increase of plasma concentration of buspirone, losartan, diltiazem, felodipine, midazolam, cyclosporine, triazolam, verapamil, carbamazepine, diltiazem, aripiprazole, tamoxifen, doxorubicin, paclitaxel, nicardipine. Interactions between Pchs and drugs affect the gene expression and enzymatic activity of CYP3A and P-gp transporter, which has an impact on their bioavailability; such that co-administration of drugs with food, beverages and food supplements can cause a subtherapeutic effect or overdose. Therefore, it is important for the clinician to consider these interactions to obtain a better therapeutic effect.
- StatPearls: Prescription of Controlled Substances: Benefits and Risks [BOOK]StatPearls. StatPearls Publishing: Treasure Island (FL)BOOK
- One of the single most difficult challenges for any prescriber is to distinguish between the legitimate prescription of controlled substances versus the prescription potentially used for illegitimate purposes. To discern the difference, prescribers need to understand the signs, symptoms, and treatment of acute and chronic pain as well as the signs and symptoms of patients misusing controlled subs…
One of the single most difficult challenges for any prescriber is to distinguish between the legitimate prescription of controlled substances versus the prescription potentially used for illegitimate purposes. To discern the difference, prescribers need to understand the signs, symptoms, and treatment of acute and chronic pain as well as the signs and symptoms of patients misusing controlled substances.  A common reason people seek the care of medical professionals is pain relief. While many categories of pain medications are available, opioid analgesics are FDA-approved for moderate to severe pain. As such, they are a common choice for patients with acute, cancer-related, neurologic, and end-of-life pain. The prescribing of opioid analgesics for chronic pain is controversial and fraught with inconclusive standards. In the 1990s, due to the chronic failure of health professionals to undertreat severe pain, opioid analgesic prescribing was expanded. Unfortunately, this led to increased overuse, diversion of drugs, opioid use disorder, and overdose. The "Catch-22" seems to be either health professionals undertreat, and there is needless suffering, or they overtreat, with a potential to cause adverse effects like increased opioid analgesic use disorder and potential overdose. The prescription of opioid analgesics peaked in 2011. Since then, both prescribing and overdose have been declining, yet as a society, in both the lay and scientific literature, there are grave concerns that we are still in the middle of an opioid crisis.  Perhaps the biggest challenge of caring for patients with pain is that individuals have different levels of tolerance and require variable opioid doses to obtain adequate pain relief. Patients may have a range of behavioral, cultural, emotional, and psychologic responses to pain versus a substance use disorder; often, it is challenging to tell the difference. All health professionals engaged in pain management need an understanding of the treatment recommendations and safety concerns in prescribing opioid analgesics. Appropriate opioid prescribing requires a thorough patient assessment, short and long-term treatment planning, close follow-up, and continued monitoring. All providers need to be aware of not only appropriate patient assessment and treatment planning but also the possibility of use disorder, diversion, and potentially dangerous behavioral responses to controlled substances, e.g., opioid analgesics differ from pseudo-addiction and physical dependence. It is unfortunately clear that many clinicians know little about opioid use disorder. They do not understand it is a disease, and many believe opioid dependence is the same as opioid use disorder. Lack of a clear understanding results in clinicians confusing a patient with chronic non-use disorder from the one who is misusing their prescribed opioid. Lack of training and educational deficits often interfere with the appropriate prescription of opioid analgesic agents. To prevent the misuse of controlled substances, providers that prescribe controlled substances should learn prescribing practices that minimize or prevent adverse consequences.  Definitions Addiction - according to the American Society of Addiction Medicine (ASAM): "Addiction is a primary, chronic disease of brain reward, motivation, memory, and related circuitry. Dysfunction in these circuits leads to characteristic biologic, psychologic, social, and spiritual manifestations. This is reflected in an individual pathologically pursuing reward or relief by substance use and other behaviors." Addiction is now termed "use disorder," and is characterized by an inability to consistently abstain, craving the drug, impairment in behavioral control, diminished ability to recognize significant problems with one's behaviors and interpersonal relationships, and a dysfunctional emotional response. Like other chronic diseases, use disorder often involves cycles of relapse and remission. Without treatment or engagement in recovery activities, use disorder is progressive and can result in disability or premature death."  Appropriate opioid prescribing: providing pain control while minimizing toxicity, use disorder, or the risk of use disorder and implementing safeguards to reduce drug diversion. Inappropriate opioid analgesic prescribing: non-prescribing, inadequate prescribing, excessive prescribing, or continued prescribing despite evidence of the lack of effective opioid treatment. Controlled substances: drugs or medications that possess the potential for being misused and are considered to be substances that have a substantially high risk of resulting in substance use disorder. Opioid analgesics: these comprise drugs that dull the senses and relieve pain, e.g., morphine. Also, these medications may induce sleep. Please note that the Drug Enforcement Administration (DEA, USA) uses the term "narcotic" to refer to drugs that are opioid analgesics. Five Characteristics of Addiction/Use Disorder (ASAM) : 1. Craving for drug or reward. 2. Diminished recognition of significant problems in one's behavior. 3. Dysfunctional emotional response. 4. Impairment in behavioral control. 5. Inability to consistently abstain Drug Schedules of Controlled Substances All providers should be familiar with the guidelines and laws for each schedule, which have, as their basis, the purpose of the drug and the risk of use disorder. In the United States, controlled substances are under strict regulation by both federal and state laws that guide their manufacture and distribution. Controlled substances have a high risk of resulting in an addiction and substance use disorder. As the schedules decrease, I-V, the drugs listed within each category have a lower potential to cause a substance use or addiction disorder. Controlled Substance Act In the United States, the Comprehensive Drug Abuse Prevention and Control Act was passed in 1970, and it included the Controlled Substance Act. The Controlled Substance Act covers drug: Classification and regulation, according to their content and purpose. Manufacturing. Distribution. Exportation and sale. The Controlled Substance Act established five drug schedules and classified them to control their manufacture and distribution. Part of the regulation requires providers that prescribe scheduled drugs and pharmacists that fill them to obtain a license from the Drug Enforcement Administration. Health professionals' licenses include specific license numbers allowing controlled substance prescriptions to be tracked and linked to a particular provider or distributor. Of the five schedules, each has parameters based on their medical value, the risk of addiction, and the ability to cause harm. The schedules range from Schedule I (most potential for addiction and use disorder) to Schedule V (least potential for addiction/use disorder). Schedule I : Schedule I drugs possess the highest potential for use disorder and misuse. They have no medical use and are illicit or “street” drugs. Examples of Schedule I drugs include heroin, lysergic acid diethylamide, mescaline, methylenedioxymethamphetamine (MDMA), and methaqualone. Marijuana, which is legal in some states, is still classified as a Schedule I drug at the federal level as of this writing. Schedule II : Schedule II drugs have a reduced potential for use disorders than Schedule I. They are at high risk for both physical and psychological dependence. They have a high capacity for both use disorder and misuse. They are typically prescribed to treat severe pain, anxiety, insomnia, and ADHD. Examples of Schedule II substances include fentanyl, hydromorphone, meperidine, methadone, morphine, oxycodone, fentanyl, dextroamphetamine, methylphenidate, methamphetamine, pentobarbital, and secobarbital. They previously had to be prescribed only via paper prescription, but now are permitted to be electronically transmitted. (Electronic Prescribing of Controlled Substances or EPCS). No refills are allowed. Schedule II drugs have the tightest regulations when compared to other prescription drugs. Schedule III : Schedule III drugs are those with a lower misuse potential than I and II. Drugs in this category may cause physical dependence but more commonly lead to psychological dependence. Medications in this category are often used for pain control, or anesthesia, or appetite suppression. Examples of Schedule III substances include benzphetamine, ketamine, phendimetrazine, and anabolic steroids. Opioid analgesics in this schedule include products containing not more than 90 milligrams of codeine per dosage unit and buprenorphine. Schedule III drugs are prescribable verbally over the phone, with a paper prescription, or via EPCS. Within a six-month time frame, refill requirements are such that the drug can only have five refills. Schedule IV : Schedule IV drugs have an even lower misuse potential than I, II, or III. They have a limited risk of physical or psychological dependence. Examples of Schedule IV substances include: alprazolam, carisoprodol, clonazepam, clorazepate, diazepam, lorazepam, midazolam, temazepam, tramadol, and triazolam. Drugs in this class may be utilized for pain control as long as the provider deems the drug to be medically necessary and that the patient would benefit. Schedule IV drugs are prescribable verbally over the phone, with a paper prescription, or via EPCS. Refills are permitted up to five times in a six-month timeframe from the issuance date. Schedule V : Schedule V drugs are the least likely of the controlled substances to be misused. They result in very limited physical or psychological dependence. Examples include cough medicines with codeine, antidiarrheal medications that contain atropine/diphenoxylate, pregabalin, and ezogabine. Despite their low abuse potential, they still need to be managed appropriately and administered with care. When they contain codeine, it must have less than 200 mg of codeine per 100 mL. Partial prescription fills cannot occur more than six months after the date of issue. When a partial fill occurs, it is treated in the same manner and with the same rules as a refill of the drug. Drug Use Disorder, Abuse, and Misuse The use disorder of a drug differs from abuse and misuse of a drug. The drugs taken may be illicit street or stolen drugs or obtained via a legal prescription. Misusing a drug usually involves taking the drug in a harmful or detrimental way that results in personal, professional, or social problems. A patient that is abusing an opioid analgesic may no longer be appropriately interacting with their family, friends or be able to perform their duties at work. Misuse of a controlled substance refers to the use of a prescribed drug in a way that was not intended. It may be deliberate or accidental. A negative result may or may not occur. Examples of misuse include taking too much of a drug, using an incorrect dose, incorrect route, or using prescription drugs written for another person. Controlled substances include both prescription drugs and illicit drugs with no recognized medical value. Both have the potential to be abused or misused. While Schedule I drug use is illegal, prescription drugs found in Schedules II-V are also commonly abused and misused, and their misuse is a challenging problem that has increased over the last several years. The Centers for Disease Control and Prevention has declared prescription drug abuse a problem of epidemic proportions. The CDC believes that absent checks and balances on the prescription and distribution of controlled substances, including those prescribed for medical use, have the potential for abuse and that misuse will continue to increase. Pill Shopping Unfortunately, a common practice among those that deliberately misuse controlled substances is to seek out multiple sources of drugs. They do this by seeing different health care providers, and they present with a different list of complaints that are often fictitious and different for each provider. The patient may be able to obtain multiple prescriptions and then fill them at different pharmacies. Many states have enacted systems that allow providers to see all of the prescriptions written for each patient. The use of these systems is gradually curbing "pill shopping." Diversion Some prescription drugs will sell on the street for as much as $50 a tablet. Diversion is when a patient sells their drugs as a method of earning money. Drugs may also be sold to buy food, pay expenses, or purchase more potent street drugs. Worse, in some cases, healthcare providers may divert drugs from patients for the providers' own personal use or sell them to someone else. Some individuals use controlled substances in ways for which they were not originally intended. Rather than pain control, they may be used to stay awake, induce sleep, or get "high." Before the popularity of prescription drug diversion, the only method to obtain illicit drugs was to import from other countries or manufacture them in private labs. Today, law enforcement agencies have the tremendous challenge of dealing with prescription drugs sold by diversion as well as illicit drugs imported or manufactured. In both instances, these drug sales and usage result in increased criminal activity as well as dangerous overdoses and death. Methods of Obtaining Prescription Drugs A review of multiple studies demonstrates a variety of ways individuals obtain prescription drugs. The following summarizes the studies' findings. 55% free from a friend or relative. 20% from a prescriber. 10% purchased from a friend or relative. 5% stolen from a friend or relative. 5% purchased from a drug dealer. 2% from multiple doctors. 1% from theft from medical practice or pharmacy. Less 1% from internet. Studies also reveal the source of the majority of these drugs was a single legal prescriber. Provider Opioid Knowledge Deficit There are substantial knowledge gaps around appropriate and inappropriate opioid prescribing, including deficits in understanding current research, legislation, and appropriate prescribing practices. Providers often have knowledge deficits that include: Understanding of addiction. At-risk opioid addiction populations. Prescription vs. non-prescription opioid addiction. The belief that addiction and dependence on opioids is synonymous. The belief that opioid addiction is a psychologic problem instead related to a chronic painful disease. With a long history of misunderstanding, poor society, provider education, and inconsistent laws, the prescription of opioids has resulted in significant societal challenges that will only resolve with significant education and training. Misuse of Controlled Substances Unfortunately, the misuse of controlled substances resulting in morbidity and mortality is rampant. According to the National Survey on Drug Use and Health,2016, performed by the U.S. Department of Health and Human Services, over 10 million people misuse prescription pain medications, and over 2 million misuse sedatives, stimulants, and tranquilizers each year. The same study found that the most common reason for misuse is for the treatment of physical pain. The Center for Disease Control estimates more than 40,000 people die each year die from an opioid overdose. Controlled Substances There are three common classes of controlled substances commonly misused: opioids, depressants, and stimulants. Opioids Opioids are prescribed for pain control by binding to mu-opioid receptors in the central nervous system reducing pain signals to the brain as well as receptors in the GI tract and respiratory system, and are used to treat pain, diarrhea, and cough. Common Opioids Codeine - One of the most commonly taken opioid medications. It is at the center of the opioid addiction problem in the United States and thus is highly regulated. Its main indication is for pain and cough. FDA-Approved Indication Pain Codeine plays a role in the treatment of mild to moderate pain. Its use is recognized in chronic pain due to ongoing cancer and palliative care. However, the use of codeine to treat other types of chronic pain remains controversial. Chronic pain, defined by the International Association for the Study of Pain, is pain persisting beyond the standard tissue healing time, which is three months. The most prevalent causes of non-cancer chronic pain include back pain, fibromyalgia, osteoarthritis, and headache. Non-FDA Approved Indications Cough Codeine is useful in the treatment of various etiologies producing chronic cough. Also, 46% of patients with chronic cough do not have a distinct etiology despite a proper diagnostic evaluation. Codeine produces a decrease in cough frequency and severity in these patients. However, there is limited literature demonstrating the efficacy of codeine in chronic cough. The dose can vary from 15 mg to 120 mg a day. It is, however, indicated in the management of prolonged cough (in specific populations like lung cancer) usually as 30 mg every 4 to 6 hours as needed. Restless Leg Syndrome Codeine is effective in treating restless leg syndrome when given at night time, especially for those whose symptoms are not relieved by other medications. Persistent Diarrhea (Palliative) Codeine and loperamide are equally effective, and the choice between them has its basis in the assessment of the physician evaluating the small but undoubted addictive potential of codeine versus the higher cost of loperamide, and an individual difference in patient's vulnerability to adverse effects. Fentanyl - Transdermal patch and IV, commonly abused and used in mixture with other drugs. Fentanyl is a synthetic opioid that is 80-100 times stronger than morphine and is often added to heroin to increase its potency. It can cause severe respiratory depression and death, particularly mixed when mixed with other drugs or alcohol. It has a high addiction potential. Hydrocodone - Hydrocodone is a schedule II semi-synthetic opioid medication used to treat pain. Immediate-release (IR) hydrocodone is available as a combination product (combined with acetaminophen, ibuprofen, etc.) and is FDA approved for the management of pain severe enough to require an opioid analgesic and for which alternative (non-opioid) treatments are inadequate. Single-entity hydrocodone is only available in extended-release (ER) formulations. It is FDA approved to treat persistent pain severe enough to require 24-hour, long-term opioid treatment, and for which alternative treatments are inadequate. Hydrocodone is also an antitussive and indicated for cough in adults. Morphine Sulfate - FDA-approved usage of morphine sulfate includes moderate to severe pain that may be acute or chronic. Most commonly used in pain management, morphine provides significant relief to patients afflicted with pain. Clinical situations that benefit significantly by medicating with morphine include managing palliative/end-of-life care, active cancer treatment, and vaso-occlusive pain during sickle cell crisis. Morphine is widely used off-label for almost any condition that causes pain. In the emergency department, morphine is given for musculoskeletal pain, abdominal pain, chest pain, arthritis, and even headaches when patients fail to respond to first and second-line agents. Morphine is rarely used for procedural sedation. However, clinicians will sometimes combine a low dose of morphine with a low dose of benzodiazepine-like lorazepam for small procedures. Oxycodone - An opioid agonist prescription medication. The oxycodone immediate-release formulation is FDA-approved for the management of acute or chronic moderate to severe pain for which other treatments do not suffice, and for which the use of opioid medication is appropriate. The extended-release formulation is FDA-approved for the management of pain severe enough to require continuous (24 hours per day), long-term opioid treatment, and for which there are no alternative options to treat the pain. The oxycodone to morphine dose equivalent ratio is approximately 1 to 1.5 for immediate-release and 1 to 2 for extended-release formulations. Tramadol - Tramadol is an FDA approved medication for pain relief. It has specific indications for moderate to severe pain. It is considered a class IV drug by the FDA. Due to possible abuse and addiction potential, limitations to its use should be for pain that is refractive to other pain medication, such as non-opioid pain medication. There are two forms of tramadol: extended-release and immediate release. The immediate-release is not for use as an "as needed" medication; instead, it is for pain of less than a week duration. For pain lasting more than a week, extended-release is the therapeutic choice — the indication for extended-release is for pain control under 24-hour management or an extended period. Off-label, the drug is useful for premature ejaculation and restless leg syndrome refractory to other medications. For the off-label use of tramadol for premature ejaculation, both sporadic and daily use is effective for the treatment of the condition. Patients indicate a preference for "as needed" therapy for premature ejaculation due to the lack of side effects compared to the daily use of tramadol. Addiction, Dependence, and Tolerance While each of these terms is similar, providers should be aware of the differences. Addiction - the constant need for a drug despite harmful consequences. Pseudoaddiction - constant fear of being in pain, hypervigilance; usually, there is a resolution with pain resolution. Dependence - physical adaptation to a medication where it is necessary for normal function and withdrawal occurs with lack of the medication. Tolerance - lack of expected response to a medication increasing dose to achieve the same pain relief resulting from CNS adaptation to the medication over time.
- Pharmacotherapeutic management of insomnia and effects on sleep processes, neural plasticity, and brain systems modulating stress: A narrative review. [Review]Front Neurosci. 2022; 16:893015.FN
- CONCLUSIONS: Current models of insomnia may lead us to revise the way in which we use hypnotic compounds in clinical practice. Specifically, compounds should target sleep processes, the stress system, and sustain neural plasticity. In this framework, among the short/medium acting hypnotic benzodiazepines, triazolam has been the most studied compound while among the Z-drugs eszopiclone has demonstrated interesting effects. Both offer potential new insight for treating insomnia.
- Oral Sedation is Non-Inferior to Intravenous Sedation for Cornea and Glaucoma Surgery: A Randomized Controlled Trial. [Clinical Trial]Clin Ophthalmol. 2022; 16:2105-2117.CO
- CONCLUSIONS: Our results suggest that an initial dose of oral triazolam is equivalent to IV midazolam for non-cataract anterior segment surgeries. However, there was a relatively high need for supplemental IV anesthesia during some surgery types, particularly with glaucoma tube shunt implantation.
- Daridorexant (Quviviq) for insomnia. [Journal Article]Med Lett Drugs Ther. 2022 07 11; 64(1654):107-110.ML
- Population-based signals of benzodiazepine drug interactions associated with unintentional traumatic injury. [Journal Article]J Psychiatr Res. 2022 07; 151:299-303.JP
- Benzodiazepine receptor agonists and related medications, such as Z-drugs and dual orexin receptor antagonists (BZDs), have been associated with unintentional traumatic injury due to their central nervous system (CNS)-depressant effects. Drug-drug interactions (DDIs) may contribute to the known relationship between BZD use and unintentional traumatic injury, yet evidence is still lacking. We cond…
Benzodiazepine receptor agonists and related medications, such as Z-drugs and dual orexin receptor antagonists (BZDs), have been associated with unintentional traumatic injury due to their central nervous system (CNS)-depressant effects. Drug-drug interactions (DDIs) may contribute to the known relationship between BZD use and unintentional traumatic injury, yet evidence is still lacking. We conducted high-throughput pharmacoepidemiologic screening using the self-controlled case series design in a large US commercial health insurance database to identify potentially clinically relevant DDI signals among new users of BZDs. We used conditional Poisson regression to estimate rate ratios (RRs) between each co-exposure (vs. not) and unintentional traumatic injury (primary outcome), typical hip fracture (secondary outcome), and motor vehicle crash (secondary outcome). We identified 48 potential DDI signals (1.1%, involving 39 unique co-dispensed drugs), i.e., with statistically significant elevated adjusted RRs for injury. Signals were strongest for DDI pairs involving zolpidem, lorazepam, temazepam, alprazolam, eszopiclone, triazolam, and clonazepam. We also identified four potential DDI signals for typical hip fracture, but none for motor vehicle crash. Many signals have biologically plausible explanations through additive or synergistic pharmacodynamic effects of co-dispensed antidepressants, opioids, or muscle relaxants on CNS depression, impaired psychomotor and cognitive function, and/or somnolence. While other signals that lack an obvious mechanism may represent true associations that place patients at risk of injury, it is also prudent to consider the roles of chance, reverse causation, and/or confounding by indication, which merit further exploration. Given the high-throughput nature of our investigation, findings should be interpreted as hypothesis generating.
- Axial chirality and affinity at the GABAA receptor of triazolobenzodiazepines. [Journal Article]Bioorg Med Chem. 2022 06 15; 64:116758.BM
- Triazolobenzodiazepines substituted with a methyl group at the C1- and C10-positions and chloro group at C2' of pendant-phenyl were prepared and their physicochemical properties were investigated. The atropisomers of 1,10-disubstituted triazolobenzodiazepines, 1d and 1f, were isolated as (a1R, a2S) and (a1S, a2R) isomers. Their absolute configurations were determined on the basis of CD spectra in…
Triazolobenzodiazepines substituted with a methyl group at the C1- and C10-positions and chloro group at C2' of pendant-phenyl were prepared and their physicochemical properties were investigated. The atropisomers of 1,10-disubstituted triazolobenzodiazepines, 1d and 1f, were isolated as (a1R, a2S) and (a1S, a2R) isomers. Their absolute configurations were determined on the basis of CD spectra in comparison with those of stereochemically defined 9-methyl-1,4-benzodiazepin-2-ones. Examination of the affinity at the human GABAA receptors revealed that each (a1R, a2S) isomer of 1d and 1f possessed higher activity than its antipode (a1S, a2R) isomer. It was also found that 1a, which behaves achirally due to the rapid conformational change, had the highest GABAA affinity, equal to that of triazolam. Considering that each eutomer of 1d and 1f is (a1R, a2S), the conformation of 1a at the binding site of the GABAA receptor is expected to be (a1R, a2S).
- Reevaluate In Vitro CYP3A Index Reactions of Benzodiazepines and Steroids between Humans and Dogs. [Journal Article]Drug Metab Dispos. 2022 06; 50(6):741-749.DM
- Cytochrome P450 3A (CYP3A), the most important class of drug-metabolizing enzymes, participates in the metabolism of half of clinically used drugs. The CYP3A index reactions of dogs, one of the most widely used preclinical nonrodent species, are still poorly understood. This work evaluated the activity and selectivity of 10 CYP3A index reactions, including midazolam (MDZ) 1'- and 4-hydroxylation,…
Cytochrome P450 3A (CYP3A), the most important class of drug-metabolizing enzymes, participates in the metabolism of half of clinically used drugs. The CYP3A index reactions of dogs, one of the most widely used preclinical nonrodent species, are still poorly understood. This work evaluated the activity and selectivity of 10 CYP3A index reactions, including midazolam (MDZ) 1'- and 4-hydroxylation, alprazolam (APZ) and triazolam (TRZ) α- and 4-hydroxylation, testosterone (T) 6β-hydroxylation, lithocholate (LCA) 6α-hydroxylation, deoxycholate (DCA) 1β- and 5β-hydroxylation, with quantitative reaction phenotyping and kinetic analysis in human and canine recombinant CYP enzymes (rCYPs). In human studies, all reactions are reconfirmed as mixed index reactions of CYP3A with minor contributions from non-CYP3A isoforms. In canine studies, all reactions are also primarily catalyzed by CYP3A12 with lower contributions from CYP3A26. However, the canine CYP2B11 appreciably contributes to the hydroxylation of benzodiazepines except for APZ 4-hydroxylation. The canine CYP3A isoforms have lower activity than human isoforms toward T 6β-hydroxylation and LCA 6α-hydroxylation and both substrates undergo non-CYP3A catalyzed side reactions. DCA 1β- and 5β-hydroxylation are validated as the CYP3A index reactions in both humans and dogs with limited non-CYP3A contributions and side reactions. In conclusion, this work provides a comprehensive overview for the selectivity and activity of in vitro CYP3A index reactions in humans and dogs. The validated CYP3A index reactions between humans and dogs may benefit future practices in drug metabolism and drug interaction studies. SIGNIFICANCE STATEMENT: Dogs are one of the most important nonrodent animals with limited studies of cytochrome P450 enzymes than humans. This work provides the most comprehensive quantitative data to date for the selectivity and activity of CYP3A index reactions in humans and dogs. The canine CYP2B11 was found to appreciably contribute to hydroxylation of midazolam, alprazolam and triazolam, the well-known probes for human CYP3A. Deoxycholate 1β- and 5β-hydroxylation are validated as the CYP3A index reactions in both humans and dogs.
- High-Dose Benzodiazepines Positively Modulate GABAA Receptors via a Flumazenil-Insensitive Mechanism. [Journal Article]Int J Mol Sci. 2021 Dec 21; 23(1)IJ
- Benzodiazepines (BZDs) produce versatile pharmacological actions through positive modulation of GABAA receptors (GABAARs). A previous study has demonstrated that high concentrations of diazepam potentiate GABA currents on the α1β2γ2 and α1β2 GABAARs in a flumazenil-insensitive manner. In this study, the high-concentration effects of BZDs and their sensitivity to flumazenil were determined on syna…
Benzodiazepines (BZDs) produce versatile pharmacological actions through positive modulation of GABAA receptors (GABAARs). A previous study has demonstrated that high concentrations of diazepam potentiate GABA currents on the α1β2γ2 and α1β2 GABAARs in a flumazenil-insensitive manner. In this study, the high-concentration effects of BZDs and their sensitivity to flumazenil were determined on synaptic (α1β2γ2, α2β2γ2, α5β2γ2) and extra-synaptic (α4β2δ) GABAARs using the voltage-clamp electrophysiology technique. The in vivo evaluation of flumazenil-insensitive BZD effects was conducted in mice via the loss of righting reflex (LORR) test. Diazepam induced biphasic potentiation on the α1β2γ2, α2β2γ2 and α5β2γ2 GABAARs, but did not affect the α4β2δ receptor. In contrast to the nanomolar component of potentiation, the second potentiation elicited by micromolar diazepam was insensitive to flumazenil. Midazolam, clonazepam, and lorazepam at 200 µM exhibited similar flumazenil-insensitive effects on the α1β2γ2, α2β2γ2 and α5β2γ2 receptors, whereas the potentiation induced by 200 µM zolpidem or triazolam was abolished by flumazenil. Both the GABAAR antagonist pentylenetetrazol and Fa173, a proposed transmembrane site antagonist, abolished the potentiation induced by 200 µM diazepam. Consistent with the in vitro results, flumazenil antagonized the zolpidem-induced LORR, but not that induced by diazepam or midazolam. Pentylenetetrazol and Fa173 antagonized the diazepam-induced LORR. These findings support the existence of non-classical BZD binding sites on certain GABAAR subtypes and indicate that the flumazenil-insensitive effects depend on the chemical structures of BZD ligands.
- Prevalence and concentrations of sedative-hypnotic drugs in blood of drivers involved in road traffic crashes in the Padova region of Italy - not so easy to interpret. [Journal Article]Forensic Sci Int. 2022 Jan; 330:111097.FS
- CONCLUSIONS: Sedative-hypnotic drugs are medicinal substances frequently identified in drivers involved in RTA, commonly in concentrations associated with driving impairment. Besides the concentrations of drugs in blood, several factors have to be considered to conclude that a driver was impaired. The frequent association with alcohol, cocaine and other BZDs, confirms the abuse potential of these medications.
- Treatment of central disorders of hypersomnolence: an American Academy of Sleep Medicine systematic review, meta-analysis, and GRADE assessment. [Meta-Analysis]J Clin Sleep Med. 2021 09 01; 17(9):1895-1945.JC
- This systematic review provides supporting evidence for the accompanying clinical practice guideline on the treatment of central disorders of hypersomnolence in adults and children. The review focuses on prescription medications with U.S. Food & Drug Administration approval and nonpharmacologic interventions studied for the treatment of symptoms caused by central disorders of hypersomnolence.
This systematic review provides supporting evidence for the accompanying clinical practice guideline on the treatment of central disorders of hypersomnolence in adults and children. The review focuses on prescription medications with U.S. Food & Drug Administration approval and nonpharmacologic interventions studied for the treatment of symptoms caused by central disorders of hypersomnolence.
- Past-year use or misuse of an opioid is associated with use of a sedative-hypnotic medication: a US National Survey on Drug Use and Health (NSDUH) study. [Journal Article]J Clin Sleep Med. 2022 Mar 01; 18(3):809-816.JC
- CONCLUSIONS: Sedative-hypnotic use is common among persons who use opioids, which is of concern given the elevated mortality risk with concurrent use of these substances.
- Leveraging Human Plasma-Derived Small Extracellular Vesicles as Liquid Biopsy to Study the Induction of Cytochrome P450 3A4 by Modafinil. [Journal Article]Clin Pharmacol Ther. 2022 02; 111(2):425-434.CP
- Preparations of plasma-derived small extracellular vesicles (sEVs) were deployed as liquid biopsy to study cytochrome P450 (CYP) 3A4 (CYP3A4) induction following modafinil 400 mg once daily × 14 days (young healthy volunteers, N = 10 subjects). Induction was confirmed using the 4β-hydroxycholesterol-to-cholesterol (4βHC/C) ratio, a plasma CYP3A4/5 biomarker, with a mean 2.1-fold increase (Day 15 …
Preparations of plasma-derived small extracellular vesicles (sEVs) were deployed as liquid biopsy to study cytochrome P450 (CYP) 3A4 (CYP3A4) induction following modafinil 400 mg once daily × 14 days (young healthy volunteers, N = 10 subjects). Induction was confirmed using the 4β-hydroxycholesterol-to-cholesterol (4βHC/C) ratio, a plasma CYP3A4/5 biomarker, with a mean 2.1-fold increase (Day 15 vs. Day 1; 90% confidence interval (CI) = 1.8-2.3; P value = 0.0004). Proteomic analysis revealed the induction (mean Day 15 vs. Day 1 fold-increase (90% CI)) of both liver (1.3 (1.1-1.5), P value = 0.014) and nonliver (1.9 (1.6-2.2), P value = 0.04) sEV CYP3A4 protein expression. In CYP3A5 nonexpresser subjects, the baseline (pre-dose) 4βHC/C plasma ratio was more highly correlated with liver sEVs (r = 0.937, P value = 0.001) than nonliver sEVs (r = 0.619, P value = 0.101) CYP3A4 protein expression. When CYP3A5 expressers (CYP3A5*1/*3) were included, the correlation with liver sEVs (r = 0.761, P value = 0.011) and nonliver sEVs (r = 0.391, P value = 0.264) CYP3A4 protein was weaker. Although modafinil-induced changes in plasma 4βHC/C ratio did not correlate with sEVs CYP3A4 protein expression, the individual subject sEVs proteomic data were used successfully to predict victim drug (midazolam, triazolam, dextromethorphan, 17α-ethinylestradiol, and abemaciclib) area under the plasma concentration-time curve (AUC) ratios (AUCRs) following modafinil. Based on the AUCR values, modafinil was classified as a weak to moderate CYP3A4 inducer (vs. rifampicin). For the first time, it was possible to deploy plasma-derived sEVs to study CYP3A4 induction beyond rifampicin, a more potent CYP3A4 inducer.
- PBPK Analysis to Study the Impact of Genetic Polymorphism of NAT2 on Drug-Drug Interaction Potential of Isoniazid. [Journal Article]Pharm Res. 2021 Sep; 38(9):1485-1496.PR
- CONCLUSIONS: The novel outcome of the present study is the indication that prescribers should give careful consideration while advising CYP2C19 and CYP3A4 substrate drugs to subjects who are on prophylaxis INH therapy, and are slow to metabolic acetylation.
- Facile Fabrication of Diatomite-Supported ZIF-8 Composite for Solid-Phase Extraction of Benzodiazepines in Urine Samples Prior to High-Performance Liquid Chromatography. [Journal Article]Molecules. 2021 Aug 27; 26(17)M
- A novel diatomite-supported zeolitic imidazolate framework-8 sorbent (ZIF-8@Dt-COOH) was in situ fabricated and developed for solid-phase extraction of three benzodiazepines (triazolam, midazolam and diazepam) in urine followed by high-performance liquid chromatography. ZIF-8@Dt-COOH was easily prepared by coating ZIF-8 on the surface of Dt-COOH and characterized by Fourier transform infrared spe…
A novel diatomite-supported zeolitic imidazolate framework-8 sorbent (ZIF-8@Dt-COOH) was in situ fabricated and developed for solid-phase extraction of three benzodiazepines (triazolam, midazolam and diazepam) in urine followed by high-performance liquid chromatography. ZIF-8@Dt-COOH was easily prepared by coating ZIF-8 on the surface of Dt-COOH and characterized by Fourier transform infrared spectra, X-ray powder diffractometry and scanning electron microscopy. Compared with bare Dt-COOH, the extraction efficiency of ZIF-8@Dt-COOH for the target was significantly increased from 20.1-39.0% to 100%. Main extraction parameters, including ionic strength and pH of solution, loading volume, washing solution, elution solvent and elution volume, were optimized in detail. Under optimum conditions, the developed method gave linearity of three BZDs in 2-500 ng/mL (r ≥ 0.9995). Limits of detection (S/N = 3), and limits of quantification (S/N = 10) were 0.3-0.4 ng/mL and 1.0-1.3 ng/mL, respectively. In addition, the average recoveries at three spiked levels (5, 10 and 20 ng/mL) varied from 80.0% to 98.7%, with the intra-day and inter-day precisions of 1.4-5.2% and 1.5-8.2%, respectively. The proposed method provided an effective purification performance and gave the enrichment factors of 24.0-29.6. The proposed method was successfully employed for the accurate and sensitive determination of benzodiazepines in urine.
- Rapid determination of eight benzodiazepines in suspected counterfeit pharmaceuticals using surface-enhanced Raman scattering with handheld Raman spectrometers. [Journal Article]J Forensic Sci. 2021 Nov; 66(6):2167-2179.JF
- The excessive prescription of benzodiazepines is putting more people at risk of dependence on these drugs and is exacerbating the fatal overdose toll of opioids. A rapid and sensitive SERS method has been developed for trace detection of select benzodiazepines in low-dosage suspect counterfeit tablets, capsules, and injectable solutions using two different portable handheld Raman spectrometers eq…
The excessive prescription of benzodiazepines is putting more people at risk of dependence on these drugs and is exacerbating the fatal overdose toll of opioids. A rapid and sensitive SERS method has been developed for trace detection of select benzodiazepines in low-dosage suspect counterfeit tablets, capsules, and injectable solutions using two different portable handheld Raman spectrometers equipped with either a 785-nm laser or a 1064-nm laser. A total of 169 samples and blanks were examined using five handheld Raman spectrometers, which provided data set of 729 examinations. The extraction/SERS procedures yielded true positive rates above 90% for alprazolam, diazepam, and midazolam using the 1064-nm device and yielded true positive rates above 95% for alprazolam, clonazepam, diazepam, estazolam, midazolam, and temazepam using the 785-nm device; however, the extraction/SERS procedures yielded true positive rates below 60% for lorazepam and triazolam. The minimum concentration (Cmin) of the benzodiazepine standards that reproducibly yielded a positive match ranged from 1 to 10 μg/ml using the 1064-nm laser device and from 0.5 to 50 μg/ml using the 785-nm laser device. For the analysis of authentic and suspect counterfeit tablets containing these benzodiazepines, the measured Cmin ranged between 10 and 15 µg per tablet or capsule for 1064-nm laser device and 1-100 µg per tablet or capsule for 785-nm laser device. The developed methods are simple, rapid, and ideal for screening suspect benzodiazepine-containing pharmaceutical products at satellite laboratories located within or near international mail facilities and express courier hubs.
- Incorporation of five common hypnotics into hair after a single dose and application to a forensic case of drug facilitated crimes. [Journal Article]Forensic Sci Int. 2021 Aug; 325:110881.FS
- In order to obtain fundamental information on the disposition of hypnotics into hair after a single oral dose the quantitative hair analysis of triazolam (TZ), etizolam (EZ), flunitrazepam (FNZ), nitrazepam (NZ) and zolpidem (ZP) have been performed using a validated LC-MS/MS procedure. Hair specimens (straight, black) were collected from three subjects about one month and three months after a si…
In order to obtain fundamental information on the disposition of hypnotics into hair after a single oral dose the quantitative hair analysis of triazolam (TZ), etizolam (EZ), flunitrazepam (FNZ), nitrazepam (NZ) and zolpidem (ZP) have been performed using a validated LC-MS/MS procedure. Hair specimens (straight, black) were collected from three subjects about one month and three months after a single 0.25 mg dose of TZ, 1 mg of EZ, 2 mg of FNZ, 5 mg of NZ and 10 mg of ZP tartrate. The subjects ingested just one out of five different hypnotics on each day, each of five days in turn. All ingested hypnotics have been detected in hair from each subject both one month and three months after intake, and their concentrations were in the range of 0.023-0.043 pg/hair strand (0.077-0.36 pg/mg) for TZ, 0.11-0.63 pg/hair strand (0.44-5.2 pg/mg) for EZ, 0.14-2.6 pg/hair strand (0.56-22 pg/mg) for FNZ, 0.33-1.7 pg/hair strand (1.3-17 pg/mg) for NZ and 20-40 pg/hair strand (120-270 pg/mg) for ZP. For FNZ and NZ, not only the parent drugs but also their metabolites, 7-amino-FNZ and 7-amino-NZ, were detected in the range of 2.3-9.2 pg/hair strand (9.2-82 pg/mg) and 2.4-9.1 pg/hair strand (8.0-55 pg/mg), respectively. The calculated incorporation ratios into hair against the dose were found to exhibit similarity between the four benzodiazepines. This finding suggests the ability to apply these quantitative data to approximately estimating the amounts of other benzodiazepines, which have similar chemical structures, in hair although it should be noted that the amounts of drugs in hair varies considerably depending on the hair color. On the other hand, the incorporation ratio of ZP showed 15-29 times higher than that of TZ, indicating that lipophilic ZP was more likely to incorporate into hair than benzodiazepines. In addition, the application of the present data to a drug-facilitated sexual assault was shown.
- Exploration of inhibition potential of isoniazid and its metabolites towards CYP2E1 in human liver microsomes through LC-MS/MS analysis. [Journal Article]J Pharm Biomed Anal. 2021 Sep 05; 203:114223.JP
- Isoniazid (INH) is the first-line anti-tubercular drug that is used both for the prophylaxis as well as the treatment of tuberculosis (TB). The patients with TB are more vulnerable to secondary infections and other health complications, hence, they are usually administered a cocktail of drugs. This increases the likelihood of drug-drug interactions (DDIs). INH is clinically proven to interact wit…
Isoniazid (INH) is the first-line anti-tubercular drug that is used both for the prophylaxis as well as the treatment of tuberculosis (TB). The patients with TB are more vulnerable to secondary infections and other health complications, hence, they are usually administered a cocktail of drugs. This increases the likelihood of drug-drug interactions (DDIs). INH is clinically proven to interact with drugs like phenytoin, carbamazepine, diazepam, triazolam, acetaminophen, etc. Most of such clinical observations have been supported by in vitro inhibition studies involving INH and cytochrome P450 (CYP) enzymes. A few published in vitro studies have explored the CYP2E1 inhibition potential of INH to explain its interactions with acetaminophen and other CY2E1 substrates, such as chlorzoxazone, but none of them were able to demonstrate any significant inhibition of the enzyme by the drug. It was reported that metabolites of INH, such as acetylhydrazine and hydrazine, were bioactivated by CYP2E1, highlighting that perhaps the drug metabolites were responsible for the mechanism based inhibition (MBI) of the enzyme. Therefore, the purpose of this investigation was to explore CYP2E1 enzyme inhibition potential of INH and its four major metabolites, viz., acetylisoniazid, isonicotinic acid, acetylhydrazine and hydrazine, using human liver microsomes (HLM). Additionally, we determined the fraction unbound in microsomal incubation (fumic) for all the five compounds using equilibrium dialysis assay. We observed that INH and its metabolites had lower propensity for microsomal binding, and the metabolites also lacked the potential to inhibit CYP2E1 enzyme, either by direct inhibition or through MBI. This suggests involvement of some other mechanism to explain interactions of INH with CY2E1 substrates, signifying need of further exploration.
- In vivo evaluation of intestinal human CYP3A inhibition by macrolide antibiotics in CYP3A-humanised mice. [Journal Article]Xenobiotica. 2021 Jul; 51(7):764-770.X
- It is important to predict drug-drug interactions via inhibition of intestinal cytochrome P450 3A (CYP3A) which is a determinant of bioavailability of orally administered CYP3A substrates. However, inhibitory effects of macrolide antibiotics on CYP3A-mediated metabolism are not entirely identical between humans and rodents.We investigated the effects of macrolide antibiotics, clarithromycin and e…
It is important to predict drug-drug interactions via inhibition of intestinal cytochrome P450 3A (CYP3A) which is a determinant of bioavailability of orally administered CYP3A substrates. However, inhibitory effects of macrolide antibiotics on CYP3A-mediated metabolism are not entirely identical between humans and rodents.We investigated the effects of macrolide antibiotics, clarithromycin and erythromycin, on in vitro and in vivo metabolism of triazolam, a CYP3A substrate, in CYP3A-humanised mice generated by using a mouse artificial chromosome vector carrying a human CYP3A gene.Metabolic activities of triazolam were inhibited by macrolide antibiotics in liver and intestine microsomes of CYP3A-humanised mice.The area under the plasma concentration-time curve ratios of 4-hydroxytriazolam to triazolam after oral dosing of triazolam were significantly decreased by multiple administration of macrolide antibiotics. The plasma concentrations ratios of α-hydroxytriazolam and 4-hydroxytriazolam to triazolam in portal blood were significantly decreased by multiple administration of clarithromycin in CYP3A-humanised mice.These results suggest that intestinal CYP3A activity was inhibited by macrolide antibiotics in CYP3A-humanised mice in vitro and in vivo. The plasma concentrations of triazolam and its metabolites in the portal blood of CYP3A-humanised mice would be useful for direct evaluation of intestinal CYP3A-mediated drug-drug interactions.
- Novel and Nonroutine Benzodiazepines and Suvorexant by LC-MS-MS. [Journal Article]J Anal Toxicol. 2021 May 14; 45(5):462-474.JA
- Benzodiazepines are a commonly prescribed class of drugs that have the potential for abuse. The Palm Beach County Sheriff's Office received drug seizure submissions that included novel and/or nonroutine benzodiazepines of increasing prevalence from 2017 to 2019. This prompted the development of a method of analysis for these compounds in biological specimens. The method tests for 16 novel and non…
Benzodiazepines are a commonly prescribed class of drugs that have the potential for abuse. The Palm Beach County Sheriff's Office received drug seizure submissions that included novel and/or nonroutine benzodiazepines of increasing prevalence from 2017 to 2019. This prompted the development of a method of analysis for these compounds in biological specimens. The method tests for 16 novel and nonroutine benzodiazepines and suvorexant in whole blood by liquid chromatography-tandem mass spectrometry (LC-MS-MS). The target analytes included bromazepam, clobazam, clonazolam, clotiazepam, diclazepam, estazolam, etizolam, flualprazolam, flubromazepam, flubromazolam, loprazolam, lormetazepam, phenazepam, prazepam, suvorexant, tetrazepam and triazolam. The method uses 200 µL of sample, protein precipitation and an instrument run-time of 8 min. The limit of detection was either 1 or 5 ng/mL and the limit of quantitation was either 5 or 25 ng/mL depending on the analyte. The method was validated for quantitative analysis for 15 out of the 17 analytes. Flubromazepam and prazepam were validated for qualitative identification only. A quadratic calibration model (r2 > 0.990) with 1/x weighting was used for all analytes for quantitative analysis. The calibration range was either 5-100 or 25-500 ng/mL depending on the analyte. The coefficient of variation of replicate analyses was within 14% and bias was within ±14%. The method provides a sensitive, efficient and robust procedure for the quantitation and/or qualitative identification of select novel and nonroutine benzodiazepines and suvorexant using LC-MS-MS and a sample volume of 200 µL.
- 8-Substituted Triazolobenzodiazepines: In Vitro and In Vivo Pharmacology in Relation to Structural Docking at the α1 Subunit-Containing GABAA Receptor. [Journal Article]Front Pharmacol. 2021; 12:625233.FP
- In order to develop improved anxiolytic drugs, 8-substituted analogs of triazolam were synthesized in an effort to discover compounds with selectivity for α2/α3 subunit-containing GABAA subtypes. Two compounds in this series, XLi-JY-DMH (6-(2-chlorophenyl)-8-ethynyl-1-methyl-4H-benzo [f][1,2,4]triazolo[4,3-a][1,4]diazepine) and SH-TRI-108 [(E)-8-ethynyl-1-methyl-6-(pyridin-2-yl)-4H-benzo [f][1,2,…
In order to develop improved anxiolytic drugs, 8-substituted analogs of triazolam were synthesized in an effort to discover compounds with selectivity for α2/α3 subunit-containing GABAA subtypes. Two compounds in this series, XLi-JY-DMH (6-(2-chlorophenyl)-8-ethynyl-1-methyl-4H-benzo [f][1,2,4]triazolo[4,3-a][1,4]diazepine) and SH-TRI-108 [(E)-8-ethynyl-1-methyl-6-(pyridin-2-yl)-4H-benzo [f][1,2,4]triazolo[4,3-a][1,4]diazepine], were evaluated for in vitro and in vivo properties associated with GABAA subtype-selective ligands. In radioligand binding assays conducted in transfected HEK cells containing rat αXβ3γ2 subtypes (X = 1,2,3,5), no evidence of selectivity was obtained, although differences in potency relative to triazolam were observed overall (triazolam > XLi-JY-DMH > SH-TRI-108). In studies with rat αXβ3γ2 subtypes (X = 1,2,3,5) using patch-clamp electrophysiology, no differences in maximal potentiation of GABA-mediated Cl- current was obtained across subtypes for any compound. However, SH-TRI-108 demonstrated a 25-fold difference in functional potency between α1β3γ2 vs. α2β3γ2 subtypes. We evaluated the extent to which this potency difference translated into behavioral pharmacological differences in monkeys. In a rhesus monkey conflict model of anxiolytic-like effects, triazolam, XLi-JY-DMH, and SH-TR-108 increased rates of responding attenuated by shock (anti-conflict effect) but also attenuated non-suppressed responding. In a squirrel monkey observation procedure, both analogs engendered a profile of sedative-motor effects similar to that reported previously for triazolam. In molecular docking studies, we found that the interactions of the 8-ethynyl triazolobenzodiazepines with the C-loop of the α1GABAA site was stronger than that of imidazodiazepines XHe-II-053 and HZ-166, which may account for the non-sedating yet anxiolytic profile of these latter compounds when evaluated in previous studies.
- Chromatographic separation of the interconverting enantiomers of imidazo- and triazole-fused benzodiazepines. [Journal Article]J Chromatogr A. 2021 Jun 21; 1647:462148.JC
- The toolbox of medicinal chemists includes the 1,4-benzodiazepine scaffold as a "privileged scaffold" in drug discovery. Several biologically active small molecules containing a 1,4-benzodiazepine scaffold have been approved by the FDA for the treatment of various diseases, with most of them being used for their psychotropic effects. The therapeutic potential of 1,4-benzodiazepines has stimulated…
The toolbox of medicinal chemists includes the 1,4-benzodiazepine scaffold as a "privileged scaffold" in drug discovery. Several biologically active small molecules containing a 1,4-benzodiazepine scaffold have been approved by the FDA for the treatment of various diseases, with most of them being used for their psychotropic effects. The therapeutic potential of 1,4-benzodiazepines has stimulated the interest of synthetic chemists in developing new synthetic strategies to a range of substituted analogues for biological evaluation. A structural variation of the classical benzodiazepine skeleton is observed e.g. in alprazolam, midazolam, and related benzodiazepines, which contain a 1,2,4-triazole or an imidazole ring fused to the benzodiazepine core. Irrespective of the presence of the fused heterocyclic ring, the seven-membered diazepine ring is far from planar, and its shape resembles a twist chair. Then, the unsymmetrical substitution pattern around the seven membered cycle renders these molecules chiral, as they lack any reflection-type symmetry element. However, chirality of this molecules is labile at room temperature, becausea simple ring flipping process converts one enantiomer into the other, and 1,4-benzodiazepines exist as a mixture of rapidly interconverting conformational enantiomers in solution at or near room temperature. Physical separation of the interconverting enantiomers of diazepam and of other related 1,4-benzodiazepin-2-ones can be accomplished by low temperature HPLC on chiral stationary phases (CSPs). If the HPLC column is cooled down to temperatures where the interconversion rate is sufficiently low, compared to the chromatographic separation rate, distinct separated peaks can be observed, provided the CSP is sufficiently enantioselctive. The apparent rate constants for the on-column enantiomerization and the corresponding free energy activation barriers were obtained by simulation of exchange-deformed HPLC profiles using a computer program based on the stochastic model. Here we report on the dynamic HPLC investigations carried out on a set of fused imidazo and triazolo-benzodiazepines (alprazolam, midazolam, triazolam and estazolam) The experimental dynamic chromatograms and the corresponding interconversion barriers reported in this paper show that the third fused heterocyclic ring increase the energy barrier by 2 kcal/mol.
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- Investigating the Utility of Humanized Pregnane X Receptor-Constitutive Androstane Receptor-CYP3A4/7 Mouse Model to Assess CYP3A-Mediated Induction. [Journal Article]Drug Metab Dispos. 2021 07; 49(7):540-547.DM
- Clinical induction liability is assessed with human hepatocytes. However, underpredictions in the magnitude of clinical induction have been reported. Unfortunately, in vivo studies in animals do not provide additional insight because of species differences in drug metabolizing enzymes and their regulatory pathways. To circumvent this limitation, transgenic animals expressing human orthologs were …
Clinical induction liability is assessed with human hepatocytes. However, underpredictions in the magnitude of clinical induction have been reported. Unfortunately, in vivo studies in animals do not provide additional insight because of species differences in drug metabolizing enzymes and their regulatory pathways. To circumvent this limitation, transgenic animals expressing human orthologs were developed. The aim of this work was to investigate the utility of mouse models expressing human orthologs of pregnane X receptor, constitutive androstane receptor, and CYP3A4/7 (Tg-Composite) in evaluating clinical induction. Rifampin, efavirenz, and pioglitazone, which were employed to represent strong, moderate, and weak inducers, were administered at multiple doses to Tg-Composite animals. In vivo CYP3A activity was monitored by measuring changes in the exposure of the CYP3A probe substrate triazolam. After the in vivo studies, microsomes were prepared from their livers to measure changes of in vitro CYP3A4 activity. In both in vivo and in vitro, distinction of clinic induction was recapitulated as rifampin yielded the greatest inductive effect followed by efavirenz and pioglitazone. Interestingly, with rifampin, in vivo CYP3A activity was approximately 4-fold higher than in vitro activity. Conversely, there was no difference between in vivo and in vitro CYP3A activity with efavirenz. These findings are consistent with the report that, although rifampin exhibits differential inductive effects between the intestines and liver, efavirenz does not. These data highlight the promise of transgenic models, such as Tg-Composite, to complement human hepatocytes to enhance the translatability of clinical induction as well as become a powerful tool to further study mechanisms of drug disposition. SIGNIFICANCE STATEMENT: Underprediction of the magnitude of clinical induction when using human hepatocytes has been reported, and transgenic models may improve clinical translatability. The work presented here showcases the human orthologs of pregnane X receptor, constitutive androstane receptor, and CYP3A4/7 model, which was able to recapitulate the magnitude of clinical induction and to differentiate tissue-dependent induction observed with rifampin but not with efavirenz. These results not only foreshadow the potential application of such transgenic models in assessing clinical induction but also in further investigation of the mechanism of drug disposition.