Drug Use and Drug Policy in Hong Kong: Changing Patterns and New Challenges

This paper is a sociohistorical examination of drug misuse and drug policy in Hong Kong. It briefly traces the history of drug policy since Hong Kong became a colony of Britain in the nineteenth century, and then highlights the major drug issues that have emerged in the past several decades. Drug policy in Hong Kong has gone through three stages, from “Government Opium Monopoly” (1841–1945) to “The Prohibition Era” (1946–1960) to “Enlightened Prohibition” (1961–1995). The evolution in drug policy is analyzed in the light of both domestic and international social, economic, and political forces affecting Hong Kong. The major drug issue in the past two decades has been the trends of rising levels of drug use among young people and the increasing popularity of psychoactive drugs among young drug users. It is argued that these trends may be understood in terms of rapid social change resulting from industrialization and socioeconomic growth since the 1960s, and the presence of conditions favorable to the demand and supply of psychoactive drugs. Lastly, major challenges to future drug policy in Hong Kong are discussed. [Translations are provided in the International Abstracts Section of this issue.]     

Radioimmunoassay of Hair for Determination of Cocaine,Heroin, and Marijuana Exposure: Comparison with Self-Report

Radioimmunoassay of hair (RIAH) was compared with self-report for cocaine, heroin, and marijuana in two populations: 109 persons entering residential drug user treatment and 86 at follow-up posttreatment. Among treatment entrants, 89% of 87 RIAH cocaine-positives and 96% of 45 RIAH heroin-positives were confirmed by self-report. However, among those followed-up posttreatment, only 51% of 43 RIAH cocaine-positives and 67% of 18 RIAH heroin-positives were so confirmed. Whereas 95% of 104 self-reports of cocaine use in the combined population were confirmed by RIAH, only 69% of 80 self-reports of heroin use were. Self-report and RIAH for marijuana were weakly associated.     

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.     

Adjuvants for vaccines to drugs of abuse and addiction

Immunotherapeutic vaccines to drugs of abuse, including nicotine, cocaine, heroin, oxycodone, methamphetamine, and others are being developed. The theoretical basis of such vaccines is to induce antibodies that sequester the drug in the blood in the form of antibody-bound drug that cannot cross the blood brain barrier, thereby preventing psychoactive effects. Because the drugs are haptens a successful vaccine relies on development of appropriate hapten-protein carrier conjugates. However, because induction of high and prolonged levels of antibodies is required for an effective vaccine, and because injection of T-independent haptenic drugs of abuse does not induce memory recall responses, the role of adjuvants during immunization plays a critical role. As reviewed herein, preclinical studies often use strong adjuvants such as complete and incomplete Freund's adjuvant and others that cannot be, or in the case of many newer adjuvants, have never been, employed in humans. Balanced against this, the only adjuvant that has been included in candidate vaccines in human clinical trials to nicotine and cocaine has been aluminum hydroxide gel. While aluminum salts have been widely utilized worldwide in numerous licensed vaccines, the experience with human responses to aluminum salt-adjuvanted vaccines to haptenic drugs of abuse has suggested that the immune responses are too weak to allow development of a successful vaccine. What is needed is an adjuvant or combination of adjuvants that are safe, potent, widely available, easily manufactured, and cost-effective. Based on our review of the field we recommend the following adjuvant combinations either for research or for product development for human use: aluminum salt with adsorbed monophosphoryl lipid A (MPLA); liposomes containing MPLA [L(MPLA)]; L(MPLA) adsorbed to aluminum salt; oil-in-water emulsion; or oil-in-water emulsion containing MPLA.     

Reductions in convictions for violent crime during opioid maintenance treatment: a longitudinal national cohort study

Background

Although opioid maintenance treatment (OMT) has been found to reduce crime, less is known about its associations with violent crime. This study investigates changes in violent crime convictions prior to, during, and after OMT, and examines the relationship between violent crime convictions prior to OMT with the risk of violent and non-violent crime convictions during treatment.

Methods

The cohort comprised all who started OMT (n = 3221) in Norway between 1997 and 2003. Treatment data were cross linked with the national Crime Registry. Convictions for violent crime 3 years prior to, during, and after treatment were studied.

Results

Violent crime rates were significantly reduced during OMT compared with before treatment, for both men and women. The rate of convictions for violent crime during OMT was halved amongst those who remained in treatment. The reduction was less pronounced for those who left treatment: for this group, the rate of violent convictions after OMT was higher than before treatment. The risk of convictions for violent and non-violent crime during OMT was highest for those with violent convictions prior to treatment.

Conclusions

Violent crime is reduced during OMT. Screening for violent behaviour and violence risk assessment should be implemented in the treatment system.     

急慢性迷走神经刺激对大鼠海洛因复吸行为的影响及作用机制

目的:探讨急慢性迷走神经刺激(VNS)对大鼠海洛因复吸行为可能的干预作用及机制。方法:SD大鼠每天进行4h的海洛因自身给药训练,持续14d,建立具有强迫性觅药和给药特征的自身给药模型。随后所有大鼠植入VNS电极,恢复后进行10d的海洛因觅药行为消退训练,期间分组给予急性VNS、慢性VNS或假刺激。消退结束后测定各组大鼠条件性线索诱导下的海洛因觅药行为的恢复(即海洛因复吸行为)。免疫荧光法检测中枢核团c-Fos的表达水平。结果:海洛因复吸行为测定结果显示,与假刺激对照组比较,急性VNS组和慢性VNS组的有效鼻触数均明显降低(P<0.01)。免疫荧光的结果显示,与对照组比较,急性VNS组(P<0.05)和慢性VNS组(P<0.01)中央杏仁核(Ce)的c-Fos表达水平均明显降低,而边缘下区(IL)的c-Fos表达水平均明显升高(P<0.05)。结论:急慢性VNS均能够显著抑制大鼠的海洛因复吸行为,其机制可能与Ce和IL脑区神经元激活的改变有关。     

Naltrexone for heroin dependence treatment in St. Petersburg, Russia

Naltrexone may be more effective for treating opioid (heroin) dependence in Russia than in the U.S. because patients are mostly young and living with their parents, who can control medication compliance. In this pilot study we randomized 52 consenting patients who completed detoxification in St. Petersburg to a double blind, 6-month course of biweekly drug counseling and naltrexone, or counseling and placebo naltrexone. Significant differences in retention and relapse favoring naltrexone were seen beginning at 1 month and continuing throughout the study. At the end of 6 months, 12 of the 27 naltrexone patients (44.4%) remained in treatment and had not relapsed as compared to 4 of 25 placebo patients (16%; p<0.05). Since heroin dependence is the main way HIV is being spread in Russia, naltrexone is likely to improve treatment outcome and help reduce the spread of HIV if it can be made more widely available.     

Network therapy: decreased secondary opioid use during buprenorphine maintenance

Network therapy (NT) employs family members and/or friends to support compliance with an addiction treatment carried out in office practice. This study was designed to ascertain whether NT is a useful psychosocial adjunct, relative to a control treatment, for achieving diminished illicit heroin use for patients on buprenorphine maintenance. Patients agreeing to randomization to either NT (N = 33) or medication management (MM, N = 33) were inducted onto short-term buprenorphine maintenance and then tapered to zero dose. NT resulted in significantly more urine toxicologies negative for opioids than MM (65% vs. 45%) and more NT than MM patients (50% vs. 23%) experienced a positive outcome relative to secondary heroin use by the end of treatment. The use of NT in office practice may therefore improve the effectiveness of eliminating secondary heroin use during buprenorphine maintenance. It may also be useful in enhancing compliance with an addiction treatment regimen in other contexts.