Development of a monitoring system for heroin-assisted substitution treatment in Switzerland

OBJECTIVES: Switzerland introduced heroin-assisted treatment as a routine treatment for drug addicts. As a result the evaluation instruments were changed from a detailed scientific project to a routine monitoring system. The process for developing this monitoring system is described. METHODS: The questionnaires and assessment instruments were restyled with staff of the treatment agencies. Indicators measuring quality of treatment and measures from the future national statistic on the addiction support system were integrated into admission, course and discharge questionnaires. Currently a system for feedback to treatment agencies is being developed. RESULTS: All 21 treatment agencies are participating in the monitoring. Assessment quality is high. CONCLUSIONS: The described monitoring should provide continuous delivery of basic relevant data on patients.     

海洛因依赖对大鼠海马自发单位放电的影响

目的:探讨海洛因依赖对大鼠海马自发单位放电的影响。方法:按剂量逐日递增原则建立海洛因依赖大鼠模型作为依赖组,对照组注射等量生理盐水。用玻璃微电极细胞外记录依赖组和对照组大鼠海马神经元自发放电。结果:海洛因依赖组大鼠海马神经元自发放电的形式以单个不匀为主(62.96%),而对照组则以单个不匀(44.30%)和混合型(36.71%)为主,组间差异显著(P<0.05);依赖组大鼠海马自发放电频率以低频(48.15%)和中频(44.44%)为主,对照组则以低频为主(58.23%),但组间差异不显著(P>0.05)。结论:海洛因依赖使大鼠海马自发单位放电发生了改变。     

男性海洛因依赖者渴求与心身症状的相关研究

目的了解男性海洛因依赖者(MPHD)渴求的影响因素。方法采用一般情况问卷(自拟)、渴求问卷(HCQ)、症状自评量表(SCL-90)、多伦多述情障碍量表(TAS)、抑郁自评问卷(SDS)、焦虑自评问卷(SAS)对湖南地区218名男性海洛因依赖者进行测评。结果渴求随吸毒年限的延长而逐渐加重(P<0.05或P<0.01)。HCQ中除“自我控制”因子外,与SDS、SAS总分、SCL-90总分及各因子均显著正相关(P<0.05或P<0.01),相关值在0.168~0.375之间。以HCQ总分为因变量进行多元回归分析,海洛因使用年限、SCL-90偏执因子、SAS总分、日吸烟量依次进入回归方程,标准化回归系数分别为0.099,0.321,0.032,0.022。结论MPHD有严重的药物渴求,渴求受多种因素影响。     

住院海洛因依赖者阿片类药物过量的危险因素分析

目的:了解住院海洛因依赖患者在脱毒过程中发生阿片类药物过量中毒的危险要素。方法:采用回顾性资料,对22例发生阿片类中毒的住院海洛因依赖患者及200例未发生中毒的患者进行相关因素对比研究并作Logistic多元回归分析,找出危险因素。结果:合并呼吸道感染、肝功能异常、合并使用抗精神病药物、既往有脑外伤或脑器质性疾病史以及住院第3～5天是住院海洛因依赖患者发生阿片类药物中毒的危险因素。结论:海洛因依赖患者往往合并有多种躯体疾病或脑外伤等疾病史,应详细询问病史及检查躯体,对有呼吸道感染、肝功能异常以及有脑外伤或脑器质性疾病者慎用药,美沙酮用量可酌情减少或分次服用,入院时应查血常规、肝功能等。     

Concurrent heroin self-administration and intracranial self-stimulation in rats

In a two-lever testing chamber, rats lever pressed for lateral hypothalamic brain stimulation or intravenous heroin reinforcers on a concurrent FR1 FR1 schedule of reinforcement. Responding for stimulation did not alter the rate of heroin self-administration, and responding for heroin caused increased responding for stimulation. Discontinuing heroin injections, or administering 3 mg/kg of naloxone, disrupted responding for both reinforcers, while changing the unit dose of heroin did not appreciably affect response rates for stimulation. This experiment demonstrates that rats are able to lever press during the period between successive self-administered heroin infusions, suggesting that the pausing normally seen between infusions is not due to debilitation, stereotyping, or sedation.     

The dissociation of heroin-seeking patterns induced by contextual,discriminative, or discrete conditioned cues in a model of relapse to heroin in rats

Rationale The role of heroin-related stimuli in motivating the resumption of heroin use is not fully understood. Objectives The objective was to characterize the relative importance of drug-related contextual stimuli, discriminative stimuli (DS), or discrete conditioned stimuli (CSs) on drug seeking when rats were reintroduced into the operant context after withdrawal. Methods Nose-poke responding by male rats was reinforced with intravenous heroin (0.05 mg/kg per infusion, 4-h session daily) under a progressive ratio schedule of reinforcement for 14 days. Each session began with the illumination of a green light in the active hole that served as DS. Each earned heroin injection was paired with a 5-s compound cue light and the sound of the infusion pump that served as the discrete CSs. Results Response rates of heroin seeking induced by the contextual stimuli were comparable to the average rates of responding during self-administration training, but rates induced by either DS or CSs were greater than those induced by the contextual stimuli alone (P<0.05). The responding induced by contingent presentations of CSs was higher than that of DS after extinction of instrumental behavior. The drug seeking induced by CSs can be maintained after 3 days extinction with DS in the original context, although the responding elicited by DS cannot be recovered after 3 days of extinction with CSs. Conclusions The relapse to drug seeking can be elicited separately by environmental cues, heroin-predictive DS, or discrete CSs in the same rat after withdrawal.     

Involvement of mu-, delta- and kappa-opioid receptor subtypes in the discriminative-stimulus effects of delta-9-tetrahydrocannabinol (THC) in rats

Rationale Many behavioral effects of delta-9-tetrahydrocannabinol (THC), including its discriminative-stimulus effects, are modulated by endogenous opioid systems.Objective To investigate opioid receptor subtypes involved in the discriminative effects of THC.Methods Rats trained to discriminate 3 mg/kg i.p. of THC from vehicle using a two-lever operant drug-discrimination procedure, were tested with compounds that bind preferentially or selectively to either mu-, delta- or kappa-opioid receptors.Results The preferential mu-opioid receptor agonist heroin (0.3–1.0 mg/kg, i.p.), the selective delta-opioid receptor agonist SNC-80 (1–10 mg/kg, i.p.) and the selective kappa-opioid receptor agonist U50488 (1–10 mg/kg, i.p.) did not produce generalization to the discriminative effects of THC when given alone. However, heroin, but not SNC-80 or U50488, significantly shifted the dose–response curve for THC discrimination to the left. Also, the preferential mu-opioid receptor antagonist naltrexone (0.1–1 mg/kg, i.p.), the selective delta-opioid receptor antagonist, naltrindole (1–10 mg/kg, i.p.) and the kappa-opioid receptor antagonist nor-binaltorphimine (n-BNI, 5 mg/kg, s.c.), did not significantly reduce the discriminative effects of the training dose of THC. However, naltrexone, but not naltrindole or n-BNI, significantly shifted the dose–response curve for THC discrimination to the right. Finally, naltrexone, but not naltrindole or n-BNI, blocked the leftward shift in the dose–response curve for THC discrimination produced by heroin.Conclusions mu- but not delta- or kappa-opioid receptors are involved in the discriminative effects of THC. Given the role that mu-opioid receptors play in THCs rewarding effects, the present findings suggest that discriminative-stimulus effects and rewarding effects of THC involve similar neural mechanisms.     

Reconditioning of drug-related cues: a potential contributor to relapse after drug reexposure

To investigate the process of relapse to drug seeking caused by reexposure to drugs, we studied the consequences of recurring instances of stimuli–drug associations using heroin conditioned place preference (CPP) in rats. After original conditioning and extinction, rats received either a single compartment–heroin pairing (reconditioning) or were primed with heroin and tested for reinstatement of CPP. It was found that the session of reconditioning, but not the session of reinstatement, caused the reappearance of a preference for the heroin-paired compartment on a test given 24 h later, in drug-free conditions. The effect of reconditioning was found to be dependent on heroin doses, and was not seen when heroin injections were given outside the conditioning environment. Furthermore, a single session of reconditioning elevated heroin seeking even on a test given 96 h later. Finally, heroin seeking was found to be significantly elevated on a test given 28 days after the last extinction session whether animals received 1 or 3 reconditioning sessions. These results suggest that the motivational value of cues associated with heroin is not eliminated by extinction and, importantly, that these cues can rapidly regain their ability to promote drug seeking behavior if they are re-associated with the effect of heroin.     

Naloxone distribution and cardiopulmonary resuscitation training for injection drug users to prevent heroin overdose death: A pilot intervention study

Fatal heroin overdose has become a leading cause of death among injection drug users (IDUs). Several recent feasibility studies have concluded that naloxone distribution programs for heroin injectors should be implemented to decrease heroin overdose deaths, but there have been no prospective trials of such programs in North America. This pilot study was undertaken to investigate the safety and feasibility of training injection drug using partners to perform cardiopulmonary resuscitation (CPR) and administer naloxone in the event of heroin overdose. During May and June 2001, 24 IDUs (12 pairs of injection partners) were recruited from street settings in San Francisco. Participants took part in 8-hour training in heroin overdose prevention, CPR, and the use of naloxone. Following the intervention, participants were prospectively followed for 6 months to determine the number and outcomes of witnessed heroin overdoses, outcomes of participant interventions, and changes in participants’ knowledge of overdose and drug use behavior. Study participants witnessed 20 heroin overdose events during 6 months follow-up. They performed CPR in 16 (80%) events, administered naloxone in 15 (75%) and did one or the other in 19 (95%). All overdose victims survived. Knowledge about heroin overdose management increased, whereas heroin use decreased. IDUs can be trained to respond to heroin overdose emergencies by performing CPR and administering naloxone. Future research is needed to evaluate the effectiveness of this peer intervention to prevent fatal heroin overdose.     

Acupuncture for substance abuse treatment in the downtown eastside of Vancouver

In British Columbia, Canada, the City of Vancouver’s notorious Downtown Eastside (DES) represents the poorest urban population in Canada. A prevalence rate of 30% for HIV and 90% for hepatitis C makes this a priority area for public-health interventions aimed at reducing the use of infected drugs. This study examined the utility of acupuncture treatment in reducing substance use in the marginalized, transient population. Acupuncture was offered on a voluntary, drop-in basis 5 days per week at two community agencies. During a 3-month period, the program generated 2,755 client visits. A reduction in overall use of substances (P=.01) was reported by subjects in addition to a decrease in intensity of withdrawal symptoms including “shakes”, stomach cramps, hallucinations, “muddle-headedness,” insomnia, muscle aches, nausea, sweating, heart palpitations, and feeling suicidal, P<.05. Acupuncture offered in the context of a community-based harm reduction model holds promise as an adjunct therapy for reduction of substance use.