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- Citalopram Overdose: a Fatal Case. [JOURNAL ARTICLE]
- J Med Toxicol 2014 Oct 18.
Citalopram is a selective serotonin reuptake inhibitor (SSRI) with cardiac and neurologic toxicities as well as the potential for serotonin syndrome. In most instances, patients recover fully from toxic ingestions of SSRIs. We describe a fatal case of a citalopram overdose.A 35-year-old woman presented to the emergency department after having witnessed seizures at home. An empty citalopram prescription bottle was located, and an intentional overdose was suspected. At the scene, she was found to be in cardiac arrest with pulseless electrical activity and underwent cardiopulmonary resuscitation, including intravenous epinephrine and bicarbonate. In the emergency department, her physical exam was notable for cough and gag reflexes and movement in all extremities with increased muscle tone and tachycardia. Her initial postresuscitation ECG showed sinus rhythm with QRS 92 ms and QTc 502 ms. Her temperature was initially normal, but she rapidly became febrile to 41.8 °C shortly after admission. She was treated symptomatically and with cyproheptadine for suspected serotonin syndrome (SS) but became increasingly hemodynamically unstable over the next 6 h and then developed torsades des pointes (TdP) progressing to pulseless, wide complex tachycardia. She underwent cardiopulmonary resuscitation (CPR) for approximately 50 min but ultimately expired. Postmortem serum analysis revealed a citalopram concentration of 7300 ng/mL (therapeutic range 9-200 ng/mL) and THC, but no other non-resuscitation drugs or substances.Citalopram overdoses often have only mild to moderate symptoms, particularly with ingestions under 600 mg in adults. However, with higher doses, severe manifestations have been described, including QTc prolongation, TdP, and seizures. Serotonin syndrome has also been described in SSRI overdose, and our patient exhibited signs consistent with SS, including increased muscle tone and autonomic dysregulation. Our patient's serum concentration suggests a massive overdose, with major clinical effects, possible SS, and death.Although most patients recover from citalopram overdose, high-dose ingestions can produce severe effects and fatalities may occur. In this case, it is likely that the patient's delayed presentation also contributed significantly to her death. The clinician must be aware of the potential for large ingestions of citalopram to produce life-threatening effects and monitor closely for the neurologic, cardiovascular, and other manifestations that, in rare cases, can be fatal.
- Sex Differences in Platelet Reactivity and Cardiovascular and Psychological Response to Mental Stress in Patients With Stable Ischemic Heart Disease: Insights From the REMIT Study. [Journal Article]
- J Am Coll Cardiol 2014 Oct 21; 64(16):1669-78.
Although emotional stress is associated with ischemic heart disease (IHD) and related clinical events, sex-specific differences in the psychobiological response to mental stress have not been clearly identified.We aimed to study the differential psychological and cardiovascular responses to mental stress between male and female patients with stable IHD.Patients with stable IHD enrolled in the REMIT (Responses of Mental Stress-Induced Myocardial Ischemia to Escitalopram) study underwent psychometric assessments, transthoracic echocardiography, and platelet aggregation studies at baseline and after 3 mental stress tasks. Mental stress-induced myocardial ischemia (MSIMI) was defined as the development or worsening of regional wall motion abnormality, reduction of left ventricular ejection fraction (LVEF) ≥8% by transthoracic echocardiography, and/or ischemic ST-segment change on electrocardiogram during 1 or more of the 3 mental stress tasks.In the 310 participants with known IHD (18% women, 82% men), most baseline characteristics were similar between women and men (including heart rate, blood pressure, and LVEF), although women were more likely to be nonwhite, living alone (p < 0.001), and unmarried (p < 0.001); they also had higher baseline depression and anxiety (p < 0.05). At rest, women had heightened platelet aggregation responses to serotonin (p = 0.007) and epinephrine (p = 0.004) compared with men. Following mental stress, women had more MSIMI (57% vs. 41%; p < 0.04), expressed more negative (p = 0.02) and less positive emotion (p < 0.001), and demonstrated higher collagen-stimulated platelet aggregation responses (p = 0.04) than men. Men were more likely than women to show changes in traditional physiological measures, such as blood pressure (p < 0.05) and double product.In this exploratory analysis, we identified clear, measurable, and differential responses to mental stress in women and men. Further studies should test the association of sex differences in cardiovascular and platelet reactivity in response to mental stress and long-term outcomes. (Responses of Myocardial Ischemia to Escitalopram Treatment [REMIT]; NCT00574847).
- Patient-Centric Blood Pressure Targeted CPR Improves Survival from Cardiac Arrest. [JOURNAL ARTICLE]
- Am J Respir Crit Care Med 2014 Oct 16.
Rationale: While current resuscitation guidelines are rescuer focused, the opportunity exists to develop patient centered resuscitation strategies that optimize the hemodynamic response of the individual in the hopes to improve survival. Objectives: To determine if titrating cardiopulmonary resuscitation (CPR) to blood pressure would improve 24-hour survival compared with traditional CPR in a porcine model of asphyxia-associated ventricular fibrillation (VF). Methods: After 7 minutes of asphyxia, followed by VF, 20 female 3-month old swine randomly received either: 1) blood pressure targeted care: titration of compression depth to a systolic blood pressure of 100 mmHg and vasopressors to a coronary perfusion pressure > 20 mmHg (BP care); or 2) Optimal American Heart Association Guideline care: depth of 51mm with standard advanced cardiac life support epinephrine dosing (Guideline care). All animals received manual CPR for 10 minutes before first shock. Primary outcome was 24-hour survival. Measurements and Main Results: 24-hour survival was higher in the BP care group (8/10) compared to Guideline care (0/10); p=0.001. Coronary perfusion pressure was higher in the BP care group (point estimate +8.5 mmHg, CI95 3.9 - 13.0 mmHg; p<0.01); however, depth was higher in Guideline care (point estimate +9.3 mm, CI95 6.0 - 12.5 mm; p<0.01). Number of vasopressor doses prior to first shock was higher in the BP care group vs. Guideline care (median 3 [range 0 - 3] vs. 2 [range 2 - 2]; p=0.003). Conclusions: Blood pressure targeted CPR improves 24-hour survival compared to optimal American Heart Association care in a porcine model of asphyxia-associated ventricular fibrillation cardiac arrest.
- Rescue therapy with Polymyxin B hemoperfusion in high dose vasopressor therapy Refractory Septic Shock. [JOURNAL ARTICLE]
- Minerva Anestesiol 2014 Oct 16.
Refractory septic shock (RSS) requiring major vasopressor support is associated with high mortality, especially in Gram--negative infections. The study aim was to describe hemodynamics, organ failure, and clinical outcomes in high--dose vasopressor therapy (HDVT) RSS patients treated with Polymyxin B hemoperfusion (PMX--HP) as rescue therapy.We retrospectively analyzed 52 patients, unresponsive to conventional therapy, treated with two sessions of PMX--HP requiring HDVT (norepinephrine and/or epinephrine requirement (NEP+EP) ≥0.5 μg/kg/min), ≥2 organ failures, and suspected/confirmed Gram--negative infection from any source.At baseline, mean arterial pressure (MAP) was 80±13 mmHg and NEP+EP requirement was 1.11±0.56 μg /kg/min. After two PMX--HP sessions, at 72 h, MAP significantly increased and NEP+EP requirement decreased respectively by 12% and 76%. Pulmonary and renal function also improved significantly. Thirty patients (58%) showed a ≥50% reduction in NEP+EP dose within only 24 h after the first PMX--HP session (early responders), and 22 did not or died from irreversible shock in the same time frame (early non--responders). The 30--day hospital mortality was 29%; it was 16% in early responders and 45% in early non--responders. On multivariate analysis, SAPS II score, vasopressin, and central venous pressure significantly affected 30--day hospital mortality.This is the first study describing the use of PMX--HP as a rescue therapy in RSS patients with HDVT and MOF. Our results suggest a possible role for PMX--HP in improving hemodynamics, organ function, and mortality in RSS, with a 30--day survival of up to 70%.
- Decreased Threshold of Aggregation to Low-Dose Epinephrine is Evidence of Platelet Hyperaggregability in Patients with Thrombosis. [Journal Article]
- Hematol Rep 2014 Aug 26; 6(3):5326.
Sticky platelet syndrome has been described as a hereditary thrombophilic condition. The aim of this study is to identify the presence of platelet hyperaggregability in patients who have experienced thrombosis. Light-transmittance platelet aggregometry was used to assess for spontaneous platelet aggregation, aggregation in response to full and low-dose (LD) epinephrine (Epi) and adenosine diphosphate, as well as arachidonic acid, and identify a distinct pattern of platelet hyperaggregability. Light-transmittance platelet aggregometry results were correlated with PFA-100® (Dade-Behring, Marburg, Germany) results, when available. An exaggerated response to LD Epi was found in 68% of patients with thrombosis compared to only 36% of healthy controls (P=0.034). Patients with thrombosis, either arterial or venous, demonstrated an exaggerated response to LD Epi nearly twice as frequently as healthy controls, even without significant family history of thrombophilia or other known risk factors for thrombosis. This suggests that platelet hyperaggregability may be multifactorial in nature and not necessarily hereditary.
- Comparative efficacy and the window of radioprotection for adrenergic and serotoninergic agents and aminothiols in experiments with small and large animals. [REVIEW]
- J Radiat Res 2014 Oct 13.
This review gives a comparative evaluation of the radioprotective properties and the therapeutic index (TI) of radioprotectors from various pharmacological group in experiments on both small and large animals. It presents a hypothesis explaining the decrease in the TI of cystamine and 5-methoxytryptamine (mexamine), and the retention of that of α1-adrenomimetic indralin, and also compares the effects on large and small animals. The considerable differences in the therapeutic indices of catecholamines, serotonin and cystamine are a consequence of specific features of their mechanisms of radioprotective action. Radioprotectors acting via receptor mediation tend to provide a more expanded window of protection. The reduction in the TI of cystamine in larger animals, such as dogs, may be caused by the greater increase in toxicity of aminothiols in relation to the decrease in their optimal doses for radioprotective effect in going from mice to dogs, which is a consequence of the slower metabolic processes in larger animals. The somatogenic phase of intoxication by cystamine is significantly longer than the duration of its radioprotective effect, and increases with irradiation. The decrease in the radioprotective effect and the TI of mexamine in experiments with dogs may be caused by their lower sensitivity to the acute hypoxia induced by the mexamine. This is because of lower gradient in oxygen tension between tissue cells and blood capillaries under acute hypoxia that is determined by lower initial oxygen consumption in a large animal as compared with a small animal. Indralin likely provides optimal radioprotective effects and a higher TI for large animals via the increased specificity of its adrenergic effect on tissue respiration, which supports the development of acute hypoxia in the radiosensitive tissues of large animals. The stimulatory effect of indralin on early post-irradiation haematopoietic recovery cannot provide a high level of radioprotective action for large animals, but it may promote recovery.
- Epinephrine injection versus epinephrine injection and a second endoscopic method in high-risk bleeding ulcers. [JOURNAL ARTICLE]
- Cochrane Database Syst Rev 2014 Oct 13.:CD005584.
Endoscopic therapy reduces the rebleeding rate and the need for surgery in patients with bleeding peptic ulcers.To determine whether a second procedure improves haemostatic efficacy or patient outcomes or both after epinephrine injection in adults with high-risk bleeding ulcers.For our update in 2014, we searched the following versions of these databases, limited from June 2009 to May 2014: Ovid MEDLINE(R) 1946 to May Week 2 2014; Ovid MEDLINE(R) Daily Update May 22, 2014; Ovid MEDLINE(R) In-Process & Other Non-Indexed Citations May 22, 2014 (Appendix 1); Evidence-Based Medicine (EBM) Reviews-the Cochrane Central Register of Controlled Trials (CENTRAL) April 2014 (Appendix 2); and EMBASE 1980 to Week 20 2014 (Appendix 3).We included randomised controlled trials (RCTs) comparing epinephrine alone versus epinephrine plus a second method. Populations consisted of patients with high-risk bleeding peptic ulcers, that is, patients with haemorrhage from peptic ulcer disease (gastric or duodenal) with major stigmata of bleeding as defined by Forrest classification Ia (spurting haemorrhage), Ib (oozing haemorrhage), IIa (non-bleeding visible vessel) and IIb (adherent clot) (Forrest Ia-Ib-IIa-IIb).We used standard methodological procedures as expected by The Cochrane Collaboration. Meta-analysis was undertaken using a random-effects model; risk ratios (RRs) with 95% confidence intervals (CIs) are presented for dichotomous data.Nineteen studies of 2033 initially randomly assigned participants were included, of which 11 used a second injected agent, five used a mechanical method (haemoclips) and three employed thermal methods.The risk of further bleeding after initial haemostasis was lower in the combination therapy groups than in the epinephrine alone group, regardless of which second procedure was applied (RR 0.53, 95% CI 0.35 to 0.81). Adding any second procedure significantly reduced the overall bleeding rate (persistent and recurrent bleeding) (RR 0.57, 95% CI 0.43 to 0.76) and the need for emergency surgery (RR 0.68, 95% CI 0.50 to 0.93). Mortality rates were not significantly different when either method was applied.Rebleeding in the 10 studies that scheduled a reendoscopy showed no difference between epinephrine and combined therapy; without second-look endoscopy, a statistically significant difference was observed between epinephrine and epinephrine and any second endoscopic method, with fewer participants rebleeding in the combined therapy group (nine studies) (RR 0.32, 95% CI 0.21 to 0.48).For ulcers of the Forrest Ia or Ib type (oozing or spurting), the addition of a second therapy significantly reduced the rebleeding rate (RR 0.66, 95% CI 0.49 to 0.88); this difference was not seen for type IIa (visible vessel) or type IIb (adherent clot) ulcers. Few procedure-related adverse effects were reported, and this finding was not statistically significantly different between groups. Few adverse events occurred, and no statistically significant difference was noted between groups.The addition of a second injected method reduced recurrent and persistent rebleeding rates and surgery rates in the combination therapy group, but these findings were not statistically significantly different. Significantly fewer participants died in the combined therapy group (RR 0.50, 95% CI 0.25 to 1.00).Epinephrine and a second mechanical method decreased recurrent and persistent bleeding (RR 0.31, 95% CI 0.18 to 0.54) and the need for emergency surgery (RR 0.20, 95% CI 0.06 to 0.62) but did not affect mortality rates.Epinephrine plus thermal methods decreased the rebleeding rate (RR 0.49, 95% CI 0.30 to 0.78) and the surgery rate (RR 0.20, 95% CI 0.06 to 0.62) but did not affect the mortality rate.Our risk of bias estimates show that risk of bias was low, as, although the type of study did not allow a double-blind trial, rebleeding, surgery and mortality were not dependent on subjective observation. Although some studies had limitations in their design or implementation, most were clear about important quality criteria, including randomisation and allocation concealment, sequence generation and blinding.Additional endoscopic treatment after epinephrine injection reduces further bleeding and the need for surgery in patients with high-risk bleeding peptic ulcer. The main adverse events include risk of perforation and gastric wall necrosis, the rates of which were low in our included studies and favoured neither epinephrine therapy nor combination therapy. The main conclusion is that combined therapy seems to work better than epinephrine alone. However, we cannot conclude that a particular form of treatment is equal or superior to another.
- A nervous tumor microenvironment: the impact of adrenergic stress on cancer cells, immunosuppression, and immunotherapeutic response. [JOURNAL ARTICLE]
- Cancer Immunol Immunother 2014 Oct 12.
Long conserved mechanisms maintain homeostasis in living creatures in response to a variety of stresses. However, continuous exposure to stress can result in unabated production of stress hormones, especially catecholamines, which can have detrimental health effects. While the long-term effects of chronic stress have well-known physiological consequences, recent discoveries have revealed that stress may affect therapeutic efficacy in cancer. Growing epidemiological evidence reveals strong correlations between progression-free and long-term survival and β-blocker usage in cancer patients. In this review, we summarize the current understanding of how the catecholamines, epinephrine and norepinephrine, affect cancer cell survival and tumor progression. We also highlight new data exploring the potential contributions of stress to immunosuppression in the tumor microenvironment and the implications of these findings for the efficacy of immunotherapies.
- Quantification of catecholamine uptake in adult cardiac myocytes. [Journal Article]
- Methods Mol Biol 2015.:43-52.
In adult cardiac myocytes, multiple G protein-coupled receptors (GPCR) localize to and signal at the nucleus. These include endothelin B receptors, angiotensin type 1 and 2 receptors, β1- and β3-adrenergic receptors, and α1A- and α1B-adrenergic receptors. Initiation of signaling through nuclear GPCRs requires that ligands be produced within or transported into the cardiac myocytes, yet mechanisms whereby these ligands are produced or transported into cardiac myocytes are largely unclear. To activate nuclear adrenergic receptors in adult cardiac myocytes, uptake of endogenous catecholamines epinephrine and norepinephrine occurs via organic cation transporter 3 (OCT3), a member of the slc22a family of genes. This chapter details a method to detect and quantify catecholamine uptake in intact adult cardiac myocytes using a fluorescent-based catecholamine uptake assay.