- A Study of the Longitudinal Patterns of Stimulant and Amyl Nitrite Use and Sexual Behavior Pre- and Post-HIV Seroconversion Among MSM. [Journal Article]
- ABAIDS Behav 2017 Dec 16
- The use of stimulant drugs alone or in combination with amyl nitrites (stimulant/nitrites) has been associated with higher rates of risky sexual behavior and predictive of HIV infection among men who...
The use of stimulant drugs alone or in combination with amyl nitrites (stimulant/nitrites) has been associated with higher rates of risky sexual behavior and predictive of HIV infection among men who have sex with men. However, the temporal pattern of stimulant/nitrite use pre- and post-seroconversion has not been well established. This study assessed changes in stimulant/nitrite use and risky sexual behavior among seroconverting MSM over time. Data were collected in the Baltimore-Washington, DC; Pittsburgh; Chicago; and Los Angeles sites of the Multicenter AIDS Cohort Study (MACS), a longitudinal study of the natural history of HIV infection among MSM. We used propensity scores to select 1044 MSM from 7087 MACS participants composed of 348 seroconverting, 348 seronegative, and 348 seroprevalent participants matched on demographics, recruitment cohort, and study visits. We centered up to four-years of semi-annual data around the seroconversion visit of the seroconverting case within each matched group of participants. Mixed effects regressions estimated the effects of serostatus, recruitment cohort, and time on self-reported stimulant/nitrite use, numbers of male intercourse partners, and numbers of unprotected receptive anal intercourse (URAI) partners. Covariates included demographics, binge drinking, and marijuana use. Seroconverters had the highest odds of stimulant/inhaled nitrite use (AOR 10.3, CI 4.8-22.0), incident rates of intercourse (IRR 1.6, CI 1.3-2.1), and URAI partners (IRR 5.1, CI 3.5-7.3). All participants decreased drug use and sexual risk behavior over time. However, the decreases were largest for seroconverters who nevertheless maintained the highest rates of stimulant/nitrite use and sexual risk. Cohort-related effects were associated with sharp reductions in stimulant/nitrite use and URAI in the early 1990s that rebounded considerably within the first decade of the 2000s. Although all participants decreased risky sexual behavior and stimulant and/or nitrite use over time, seroconverters had the largest decreases. There was no evidence for abrupt or substantial increases in drug use or risky sex post-seroconversion. However, there was substantial variation at the individual level, with the factors underlying this variation not well understood and worth further study. Moreover, stimulant/nitrite use and risky sexual behavior appear to have been strongly influenced by contextual historical and socio-cultural effects. The manner in which contextual factors influence individual behavior is also not well understood and also warrants further study.
- Inorganic nitrite and nitrate in cardiovascular therapy: A better alternative to organic nitrates as nitric oxide donors? [Review]
- VPVascul Pharmacol 2017 Nov 22
- In 1867 the organic nitrite, amyl nitrite, was introduced as a therapeutic agent in the treatment of angina pectoris and was later substituted by the organic nitrate nitroglycerin (NTG). Despite havi...
In 1867 the organic nitrite, amyl nitrite, was introduced as a therapeutic agent in the treatment of angina pectoris and was later substituted by the organic nitrate nitroglycerin (NTG). Despite having a highly potent vasodilator capacity in veins>coronary arteries>arterioles, the vasodilator effects NTG are rapidly attenuated by the development of nitrate tolerance. We and others established that NTG treatment stimulates the production of reactive oxygen species such as superoxide and peroxynitrite with subsequent marked attenuation of the NTG vasodilator potency. The nitrite anion (NO2-) has more recently been characterized to possess novel pharmacotherapeutic actions such as modulation of vasodilation under hypoxic conditions, thereby providing protection in ischemia-reperfusion injury. Administration of NO2-/NO3-has also been shown to improve myocardial function in heart failure and to lower blood pressure. Despite these positive aspects there is still a great need to study inorganic nitrate and nitrite therapy in various cardiovascular diseases in prospective outcome directed studies. In case being successful, this kind of therapy would indeed represent a cheap, therefore affordable, effective cardiovascular therapy without major side effects as observed in response to therapy with organic nitrates.
- Comparison of Valsalva Maneuver, Amyl Nitrite, and Exercise Echocardiography to Demonstrate Latent Left Ventricular Outflow Obstruction in Hypertrophic Cardiomyopathy. [Journal Article]
- AJAm J Cardiol 2017 Dec 15; 120(12):2265-2271
- Guidelines recommend exercise stress echocardiogram (ESE) for patients with hypertrophic cardiomyopathy (HC) if a 50 mm Hg gradient is not present at rest or provoked with Valsalva or amyl nitrite, t...
Guidelines recommend exercise stress echocardiogram (ESE) for patients with hypertrophic cardiomyopathy (HC) if a 50 mm Hg gradient is not present at rest or provoked with Valsalva or amyl nitrite, to direct medical and surgical management. However, no study has directly compared all 3 methods. We sought to evaluate efficacy and degree of provocation of left ventricular outflow gradients by ESE, and compare with Valsalva and amyl nitrite. In patients with HC between 2002 and 2015, resting echocardiograms and ESEs within 1 year were retrospectively reviewed. Gradients elicited by each provocation method were compared. Rest and ESE were available in 97 patients (mean age 54 ± 18 years, 57% male); 78 underwent Valsalva maneuver and 41 amyl nitrite provocation. Median gradients (interquartile range) were 10 mm Hg (7,19) at rest, 16 mm Hg (9,34) with Valsalva, 23 mm Hg (13,49) with amyl nitrite, and 26 mm Hg (13,58) with ESE. ESE and amyl nitrite were able to provoke obstruction (≥30 mm Hg) and severe obstruction (≥50 mm Hg) more frequently than Valsalva. In patients with resting gradient <30 mm Hg (n = 83), provocation maneuvers demonstrated dynamic obstruction in 51%; in those with Valsalva gradient <30 mm Hg (n = 57), ESE or amyl nitrite provoked a gradient in 44%; and in those with amyl nitrite gradient <30 mm Hg (n = 20), ESE provoked a gradient in 29%. No demographic or baseline echocardiographic parameter predicted provocable obstruction. In conclusion, ESE is clinically useful; however, different provocation maneuvers may be effective in different patients with HC, and all maneuvers may be required to provoke dynamic obstruction in symptomatic patients.
- [Multifocal Electroretinography in Patients with Poppers Maculopathy]. [Journal Article]
- KMKlin Monbl Augenheilkd 2017 Oct 12
- BackgroundMaculopathy is a potential side effect of amyl nitrite or "poppers" abuse. It is characterized by a sudden, painless decrease in visual acuity. While the funduscopic cha...
BackgroundMaculopathy is a potential side effect of amyl nitrite or "poppers" abuse. It is characterized by a sudden, painless decrease in visual acuity. While the funduscopic changes are subtle, optical coherence tomography shows alterations of the outer retinal layers in the fovea. However, the extent of retinal dysfunction remains poorly understood.Materials/MethodsWe compared the multifocal electroretinogram of 6 patients with poppers maculopathy to that of a control group consisting of 6 healthy subjects. Response densities and implicit times of N1 and P1 were analyzed.ResultsResponse densities and implicit times of both N1 and P1 were lower in the patients with poppers maculopathy than in the control group, particularly in ring 1 and rings 4 and 5. The only statistically significant finding, however, was a reduced N1 response density of one hexagon in the patient group. No significant differences were found considering the sum response or the averaged rings 1 to 5.ConclusionCompared to a healthy control group, the multifocal electroretinogram of patients with poppers maculopathy shows no relevant impairment. This contrasts the marked effect of the disease on visual acuity. In clinical practice, poppers maculopathy cannot be diagnosed by multifocal electroretinography.
- Poppers: legal highs with questionable contents? A case series of poppers maculopathy. [Journal Article]
- BJBr J Ophthalmol 2017; 101(11):1530-1534
- CONCLUSIONS: On the basis of the products tested here, it seems that isopropyl nitrite is toxic to the fovea and can cause significant visual disturbance. The production of poppers is unregulated and their popularity is concerning, particularly given their exemption from the Psychoactive Substances Act 2016, which might suggest that they are harmless chemicals.
- Following Lives Undergoing Change (Flux) study: Implementation and baseline prevalence of drug use in an online cohort study of gay and bisexual men in Australia. [Journal Article]
- IJInt J Drug Policy 2017; 41:41-50
- CONCLUSIONS: Ease of entry and minimal research burden on participants helped ensure successful recruitment into this online cohort study. Study outcomes will include the initiation and cessation of drug use, associated risk behaviours, and health consequences, over time. Results will provide insights into the role gay community plays in patterns of drug use among GBM.
- Dangerous intoxication after oral ingestion of poppers (alkyl nitrites): Two case reports. [Case Reports]
- TTherapie 2017; 72(3):397-399
- Abuse potential and dopaminergic effect of alkyl nitrites. [Journal Article]
- NLNeurosci Lett 2016 Aug 26; 629:68-72
- The abuse of alkyl nitrites is common among adolescents and young adults worldwide. However, the information regarding the effects of alkyl nitrites on the central nervous system and the associated p...
The abuse of alkyl nitrites is common among adolescents and young adults worldwide. However, the information regarding the effects of alkyl nitrites on the central nervous system and the associated psychological abuse potential is scarce. The abuse potential of 3 representative alkyl nitrites - isobutyl nitrite, isoamyl nitrite, and butyl nitrite - was evaluated in mice using conditioned place preference tests with an unbiased method. The dopamine levels released by synaptosomes extracted from the striatal region were measured using high performance liquid chromatography. Mice treated with the test substances (50mg/kg, i.p.) exhibited a significantly increased drug-paired place preference. Moreover, greater levels of dopamine were released by striatal region synaptosomes in response to isobutyl nitrite treatment in mice. Thus, our findings suggest that alkyl nitrites could lead to psychological dependence and dopaminergic effects. Furthermore, these results provide scientific evidence to support the regulation of alkyl nitrites as psychoactive substances in the future.
- [Amyl nitrite, sodium nitrite, sodium thiosulfate]. [Review]
- CKChudoku Kenkyu 2015; 28(4):383-7
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- Neurotoxicity induced by alkyl nitrites: Impairment in learning/memory and motor coordination. [Journal Article]
- NLNeurosci Lett 2016 Apr 21; 619:79-85
- Although alkyl nitrites are used as recreational drugs, there is only little research data regarding their effects on the central nervous system including their neurotoxicity. This study investigated...
Although alkyl nitrites are used as recreational drugs, there is only little research data regarding their effects on the central nervous system including their neurotoxicity. This study investigated the neurotoxicity of three representative alkyl nitrites (isobutyl nitrite, isoamyl nitrite, and butyl nitrite), and whether it affected learning/memory function and motor coordination in rodents. Morris water maze test was performed in mice after administrating the mice with varying doses of the substances in two different injection schedules of memory acquisition and memory retention. A rota-rod test was then performed in rats. All tested alkyl nitrites lowered the rodents' capacity for learning and memory, as assessed by both the acquisition and retention tests. The results of the rota-rod test showed that isobutyl nitrite in particular impaired motor coordination in chronically treated rats. The mice chronically injected with isoamyl nitrite also showed impaired function, while butyl nitrite had no significant effect. The results of the water maze test suggest that alkyl nitrites may impair learning and memory. Additionally, isoamyl nitrite affected the rodents' motor coordination ability. Collectively, our findings suggest that alkyl nitrites may induce neurotoxicity, especially on the aspect of learning and memory function.