HIV-1 incidence among opiate users in northern Thailand.
The incidence of human immunodeficiency virus type 1 (HIV-1) infection among opiate users was determined in a retrospective cohort of 436 patients with multiple admissions to the only inpatient drug treatment program in northern Thailand between October 1993 and September 1995. During 323.4 person-years of follow-up, 60 patients presenting for detoxification acquired HIV-1 infection, for a crude incidence rate of 18.6 per 100 person-years (95% confidence interval 14.4-23.9). All seroconverters were male. HIV-1 incidence varied by the current route of drug administration: 31.3 per 100 person-years for injectors and 2.8 per 100 person-years for noninjectors (smoking and ingestion). Significant differences were found by ethnicity: HIV-1 incidence was 29.3 per 100 person-years for Thai lowlanders and 8.5 per 100 person-years for hill tribes. Multivariate relative risk estimates showed that injecting opiates (vs. use by other routes), being unmarried, being under age 40 years, being a Thai lowlander, having a primary and secondary education, and being employed in the business sector were each independently associated with human immunodeficiency virus seroconversion. This HIV-1 incidence rate is double that reported for Bangkok and suggests that prevention and control programs for drug users need to be expanded throughout Thailand. Improved availability of more-effective treatment regimens and increased access to sterile injection equipment are needed to confront the HIV-1 epidemic among opiate users in northern Thailand. (+info)
Dissociable deficits in the decision-making cognition of chronic amphetamine abusers, opiate abusers, patients with focal damage to prefrontal cortex, and tryptophan-depleted normal volunteers: evidence for monoaminergic mechanisms.
We used a novel computerized decision-making task to compare the decision-making behavior of chronic amphetamine abusers, chronic opiate abusers, and patients with focal lesions of orbital prefrontal cortex (PFC) or dorsolateral/medial PFC. We also assessed the effects of reducing central 5-hydroxytryptamine (5-HT) activity using a tryptophan-depleting amino acid drink in normal volunteers. Chronic amphetamine abusers showed suboptimal decisions (correlated with years of abuse), and deliberated for significantly longer before making their choices. The opiate abusers exhibited only the second of these behavioral changes. Importantly, both sub-optimal choices and increased deliberation times were evident in the patients with damage to orbitofrontal PFC but not other sectors of PFC. Qualitatively, the performance of the subjects with lowered plasma tryptophan was similar to that associated with amphetamine abuse, consistent with recent reports of depleted 5-HT in the orbital regions of PFC of methamphetamine abusers. Overall, these data suggest that chronic amphetamine abusers show similar decision-making deficits to those seen after focal damage to orbitofrontal PFC. These deficits may reflect altered neuromodulation of the orbitofrontal PFC and interconnected limbic-striatal systems by both the ascending 5-HT and mesocortical dopamine (DA) projections. (+info)
Safer sex strategies for women: the hierarchical model in methadone treatment clinics.
Women clients of a methadone maintenance treatment clinic were targeted for an intervention aimed to reduce unsafe sex. The hierarchical model was the basis of the single intervention session, tested among 63 volunteers. This model requires the educator to discuss and demonstrate a full range of barriers that women might use for protection, ranking these in the order of their known efficacy. The model stresses that no one should go without protection. Two objections, both untested, have been voiced against the model. One is that, because of its complexity, women will have difficulty comprehending the message. The second is that, by demonstrating alternative strategies to the male condom, the educator is offering women a way out from persisting with the male condom, so that instead they will use an easier, but less effective, method of protection. The present research aimed at testing both objections in a high-risk and disadvantaged group of women. By comparing before and after performance on a knowledge test, it was established that, at least among these women, the complex message was well understood. By comparing baseline and follow-up reports of barriers used by sexually active women before and after intervention, a reduction in reports of unsafe sexual encounters was demonstrated. The reduction could be attributed directly to adoption of the female condom. Although some women who had used male condoms previously adopted the female condom, most of those who did so had not used the male condom previously. Since neither theoretical objection to the hierarchical model is sustained in this population, fresh weight is given to emphasizing choice of barriers, especially to women who are at high risk and relatively disempowered. As experience with the female condom grows and its unfamiliarity decreases, it would seem appropriate to encourage women who do not succeed with the male condom to try to use the female condom, over which they have more control. (+info)
A pilot study to determine the usefulness of the urinary excretion of methadone and its primary metabolite (EDDP) as potential markers of compliance in methadone detoxification programs.
Fourteen subjects (selected on the basis of compliance with the methadone-maintenance program prescribed by the consultant psychiatrist in charge of their treatment) undergoing opiate detoxification by methadone-replacement therapy were studied to determine if a relationship exists between the dose of methadone prescribed and the urinary excretion of methadone and/or its primary metabolite, 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP). After the derivation of this relationship, it was hoped that the urinary concentrations of methadone and/or EDDP could be used as a noninvasive technique to monitor the methadone compliance of 56 drug abusers. Despite statistically significant correlations (p<0.001) between methadone dose and urine concentrations of methadone and EDDP, the large variation in concentrations measured in the urine of drug abusers negated the possibility of any clear-cut relationship being confirmed. However, it may be possible to use excretion data to monitor individual compliance but only through long-term monitoring of individual subjects to establish their own intraindividual variation in excretion patterns. (+info)
Hyperphagia in neonates withdrawing from methadone.
AIMS: To examine whether hyperphagia is a clinically significant problem in infants born to women receiving methadone maintenance. METHODS: The volume of feeds, changes in infant body weight, as well as occurrence of adverse clinical effects in infants withdrawing from methadone were studied during the first month of life. A retrospective chart review was conducted for all infants at San Francisco General between 1992 and 1995, born to women receiving methadone maintenance during their pregnancy. Forty four infants were identified and the data obtained from hospital medical records. The daily oral intake of these infants was recorded during the first month of life. The incidence of hyperphagia (oral intake > 190 cc/kg/day) was measured. Associations between infant oral intake and maternal methadone dose were studied using correlation analysis as well as Anova for repeated measures. Adverse clinical symptoms were also recorded. A subset of premature infants was studied separately. RESULTS: The incidence of hyperphagia was 26% by day 8 and 56% by day 16 of life in the infants. Hyperphagia was not associated with maternal methadone dose or with infant withdrawal scores. Infants who were hyperphagic lost significantly more weight during the first week of life than those who were not. Despite significantly greater intake, the hyperphagic infants did not gain weight more rapidly during the first month of life compared with those infants with lower oral intake. Infants who were hyperphagic (maximum intake of 290 cc/kg/day) did not experience increased vomiting, aspiration, diarrhoea, or abdominal distention. CONCLUSIONS: Hyperphagia is commonly found in infants withdrawing from methadone and can be persistent in a significant number. Hyperphagia was not associated with either increased neonatal weight gain or with adverse gastrointestinal consequences. Hyperphagia may occur in infants withdrawing from methadone who have high metabolic demands due to clinical signs not controlled by opiate treatment. (+info)
Use of illicit drugs among high-school students in Jamaica.
Reported are the results of a survey to assess the prevalence of illicit drug use among high-school students in Jamaica. A total of 2417 high-school students in 26 schools were covered: 1063 boys and 1354 girls of whom 1317 were grade-10 students (mean age 15.7 years) and 1100 were grade-11 students (mean age 16.8 years). Of the students, 1072 and 1345 were from rural and urban schools, respectively, while 1126 and 1291 were children of parents who were professionals and nonprofessionals, respectively. The following drugs were used by the students: marijuana (10.2%), cocaine (2.2%), heroin (1.5%) and opium (1.2%). Illicit drug use among males, urban students and children of professionals was higher than that among females, rural students and children of nonprofessionals, respectively. (+info)
Population pharmacokinetics of methadone in opiate users: characterization of time-dependent changes.
AIMS: Although methadone is widely used to treat opiate dependence, guidelines for its dosage are poorly defined. There is increasing evidence to suggest that a strategy based on plasma drug monitoring may be useful to detect non-compliance. Therefore, we have developed a population-based pharmacokinetic (POP-PK) model that characterises adaptive changes in methadone kinetics. METHODS: Sparse plasma rac-methadone concentrations measured in 35 opiate-users were assessed using the P-Pharm software. The final structural model comprised a biexponential function with first-order input and allowance for time-dependent change in both clearance (CL) and initial volume of distribution (V ). Values of these parameters were allowed to increase or decrease exponentially to an asymptotic value. RESULTS: Increase in individual values of CL and increase or decrease in individual values of V with time was observed in applying the model to the experimental data. CONCLUSIONS: A time-dependent increase in the clearance of methadone is consistent with auto-induction of CYP3A4, the enzyme responsible for much of the metabolism of the drug. The changes in V with time might reflect both up- and down-regulation of alpha1-acid glycoprotein, the major plasma binding site for methadone. By accounting for adaptive kinetic changes, the POP-PK model provides an improved basis for forecasting plasma methadone concentrations to predict and adjust dosage of the drug and to monitor compliance in opiate-users on maintenance treatment. (+info)
Pentazocine-induced fibromyositis and contracture.
We report a case of myopathy, accompanied by widespread contractures predominantly involving the elbow and knee joints, following long-standing pentazocine abuse. (+info)