Further evidence for the association of GAL, GALR1 and NPY1R variants with opioid dependence.

Aim: Heroin addiction is a chronic, relapsing disease that has genetic and environmental, including drug-induced, contributions. Stress influences the development of addictions. This study was conducted to determine if variants in stress-related genes are associated with opioid dependence (OD). Patients & methods: One hundred and twenty variants in 26 genes were analyzed in 597 Dutch subjects. Patients included 281 OD in methadone maintenance with or without heroin-assisted treatment and 316 controls. Results: Twelve SNPs in seven genes showed a nominally significant association with OD. Experiment-wise significant associations (p < 0.05) were found for three SNP pairs, through an interaction effect: NPY1R/GAL rs4691910/rs1893679, NPY1R/GAL rs4691910/rs3136541 and GALR1/GAL rs9807208/rs3136541. Conclusion: This study lends more evidence to previous reports of association of stress-related variants with heroin dependence.

Association of variants of prodynorphin promoter 68-bp repeats in caucasians with opioid dependence diagnosis: Effect on age trajectory of heroin use.

The dynorphin/kappa opioid receptor (Dyn/KOR) system is involved in reward processing and dysphoria/anhedonia. Exposure to mu-opioid receptor agonists such as heroin increases expression of the prodynorphin gene (PDYN) in the brain. In this study in a Caucasian cohort, we examined the association of the functional PDYN 68-bp repeat polymorphism with opioid use disorders. In this case-control study, 554 subjects with Caucasian ancestry (142 healthy controls, 153 opioid-exposed, but never opioid dependent, NOD, and 259 with an opioid dependence diagnosis, OD) were examined for association of the PDYN 68-bp repeats with the diagnosis of opioid dependence (DSM-IV criteria), with a dimensional measure of heroin exposure (KMSK scale), and age trajectory parameters of heroin use (age of heroin first use, and age of onset of heaviest use). The PDYN 68-bp repeat genotype (classified as: "short-short" [SS], "long-long" [LL], and "short-long" [SL], based on the number of repeats) was not associated with categorical opioid dependence diagnoses. However, the LL genotype was associated with later age of first heroin use than the SS + SL genotype (19 versus 18 years; p < 0.01). This was also confirmed by a significant positive correlation between the number of repeats and the age of first use of heroin, in volunteers with OD (Spearman r = 0.16; p = 0.01). This suggests that the functional PDYN 68-bp repeat genotype is associated with the age of first use of heroin in Caucasians diagnosed with opioid dependence.

VMAT2 gene (SLC18A2) variants associated with a greater risk for developing opioid dependence.

Aim: To determine if selected serotonergic and noradrenergic gene variants are associated with heroin addiction. Subjects & methods: A total of 126 variants in 19 genes in subjects with Dutch European ancestry from The Netherlands. Subjects included 281 opioid-dependent volunteers in methadone maintenance or heroin-assisted treatment, 163 opioid-exposed but not opioid-dependent volunteers who have been using illicit opioids but never became opioid-dependent and 153 healthy controls. Results: Nominal associations were indicated for 20 variants in six genes including an experiment-wise significant association from the combined effect of three SLC18A2 SNPs (rs363332, rs363334 and rs363338) with heroin dependence (pfinal = 0.047). Conclusion: Further studies are warranted to confirm and elucidate the role of these variants in the vulnerability to opioid addiction.

Variants of opioid system genes are associated with non-dependent opioid use and heroin dependence.

BACKGROUND: Heroin addiction is a chronic, relapsing brain disease. Genetic factors are involved in the development of drug addiction. The aim of this study was to determine whether specific variants in genes of the opioid system are associated with non-dependent opioid use and heroin dependence. METHODS: Genetic information from four subject groups was collected: non-dependent opioid users (NOD) [n=163]; opioid-dependent (OD) patients in methadone maintenance treatment (MMT) [n=143]; opioid-dependent MMT-resistant patients in heroin-assisted treatment (HAT) [n=138]; and healthy controls with no history of opioid use (HC) [n=153]. Eighty-two variants in eight opioid system genes were studied. To establish the role of these genes in (a) non-dependent opioid use, and (b) heroin dependence, the following groups were compared: HC vs. NOD; HC vs. OD (MMT+HAT); and NOD vs. OD (MMT+HAT). RESULTS: Five unique SNPs in four genes showed nominally significant associations with non-dependent opioid use and heroin dependence. The association of the delta opioid receptor (OPRD1) intronic SNP rs2236861 with non-dependent opioid use (HC vs. NOD) remained significant after correction for multiple testing (OR=0.032; pcorrected=0.015). This SNP exhibited a significant gene-gene interaction with prepronociceptin (PNOC) SNP rs2722897 (OR=5.24; pcorrected=0.041) (HC vs. NOD). CONCLUSIONS: This study identifies several new and some previously reported associations of variants with heroin dependence and with non-dependent opioid use, an important and difficult to obtain group not extensively studied previously. Further studies are warranted to confirm and elucidate the potential roles of these variants in the vulnerability to illicit drug use and drug addiction.

Efficacy of cocaine contingency management in heroin-assisted treatment: Results of a randomized controlled trial.

AIMS: To determine the efficacy of contingency management (CM), targeting cocaine use, as an add-on intervention for heroin dependent patients in supervised heroin-assisted treatment (HAT) with frequent cocaine use. DESIGN: Multi-center, open-label, parallel group, randomized controlled trial. SETTING: Twelve specialized addiction treatment centers for HAT in The Netherlands; April 2006-January 2011. PARTICIPANTS: 214 chronic, treatment-refractory heroin dependent patients in HAT, with frequent cocaine use. INTERVENTIONS: Routine, daily supervised diacetylmorphine treatment, co-prescribed with oral methadone (HAT), with and without 6 months contingency management for cocaine use as an add-on intervention; HAT+CM and HAT-only, respectively. MEASUREMENTS: Primary outcome was the longest, uninterrupted duration of cocaine abstinence, based upon laboratory urinalysis. Secondary outcome measures included other cocaine-related measures, treatment retention in HAT, and multi-domain health-related treatment response. FINDINGS: In an intention-to-treat analysis, HAT+CM was more effective than HAT-only in promoting longer, uninterrupted duration of cocaine abstinence (3.7 weeks versus 1.6 weeks; negative binomial regression: Exp(B)=2.34, 95%-CI: 1.70-3.23; p<0.001). This result remained significant in sensitivity analyses and was supported by all secondary, cocaine-related outcome measures. Treatment retention in HAT was high (91.6%) with no difference between the groups. The improvement in multi-domain health-related treatment response during the trial was numerically higher in HAT+CM (from 37.4% to 53.1%; +15.7%) than in HAT-only (from 44.5% to 46.5%; +2.0%), but this difference was statistically not significant. CONCLUSIONS: Contingency management is an effective add-on intervention to promote longer, uninterrupted periods of cocaine abstinence in chronic, treatment-refractory heroin dependent patients in heroin-assisted treatment with frequent cocaine use. The trial has been registered in The Netherlands National Trial Register under clinical trial registration number NTR4728.

Craving and illicit heroin use among patients in heroin-assisted treatment.

AIMS: To investigate in heroin-assisted treatment (HAT) compared to methadone maintenance treatment (MMT): the course of heroin craving and illicit heroin use, their mutual association, and their association with multi-domain treatment response. DESIGN: RCTs on the efficacy of 12 months co-prescribed injectable or inhalable HAT compared to 12 months continued oral MMT. SETTING: Outpatient treatment in MMT- or specialized HAT-centers in the Netherlands. PARTICIPANTS: Chronic, treatment-refractory heroin dependent patients (n=73). STUDY PARAMETERS: General craving for heroin (Obsessive Compulsive Drug Use Scale); self-reported illicit heroin use; multi-domain treatment response in physical, mental and social health and illicit drug use. FINDINGS: The course of heroin craving and illicit heroin use differed significantly, with strong reductions in HAT but not in MMT. General heroin craving was significantly related to illicit heroin use. Heroin craving was not and illicit heroin use was marginally related to multi-domain treatment response, but only in MMT and not in HAT. CONCLUSIONS: Heroin craving and illicit heroin use were significantly associated and both strongly decreased in HAT but not in MMT. Craving was not related to multi-domain treatment response and illicit heroin use was marginally related to treatment response in MMT, but not in HAT. The latter was probably due to the strong reduction in illicit heroin use in most patients in HAT and the small sample size of the sub-study. It is hypothesized that the strong reductions in craving for heroin in HAT are related to the stable availability of prescribed, pharmaceutical grade heroin.

Heroin-assisted treatment in the Netherlands: History, findings, and international context.

This monograph describes the history, findings and international context of heroin-assisted treatment (HAT) in the Netherlands. The monograph consists of (1) a short introduction and seven paragraphs describing the following aspects of HAT in the Netherlands: (2) history of HAT studies and implementation of routine HAT in the Netherlands; (3) main findings on efficacy, safety and cost-effectiveness from the two randomized controlled HAT trials in the Netherlands; (4) new findings from a large cohort study on the effectiveness of HAT in routine clinical practice in the Netherlands; (5) unique data on the patient's perspective of HAT; (6) data on the pharmacological and pharmaceutical basis for HAT in the Netherlands; (7) description of the registration process; and (8) account of the international context of HAT. Together, these data show that HAT can now be considered a safe and proven-effective intervention for the treatment of chronic, treatment-resistant heroin dependent patients.

Outcome of long-term heroin-assisted treatment offered to chronic, treatment-resistant heroin addicts in the Netherlands.

AIMS: To describe 4-year treatment retention and treatment response among chronic, treatment-resistant heroin-dependent patients offered long-term heroin-assisted treatment (HAT) in the Netherlands. DESIGN: Observational cohort study. SETTING AND INTERVENTION: Out-patient treatment in specialized heroin treatment centres in six cities in the Netherlands, with methadone plus injectable or inhalable heroin offered 7 days per week, three times per day. Prescription of methadone plus heroin was supplemented with individually tailored psychosocial and medical support. PARTICIPANTS: Heroin-dependent patients who had responded positively to HAT in two randomized controlled trials and were eligible for long-term heroin-assisted treatment (n = 149). MEASUREMENTS: Primary outcome measures were treatment retention after 4 years and treatment response on a dichotomous, multi-domain response index, comprising physical, mental and social health and illicit substance use. FINDINGS: Four-year retention was 55.7% [95% confidence interval (CI): 47.6-63.8%]. TREATMENT: Response was significantly better for patients continuing 4 years of HAT compared to patients who discontinued treatment: 90.4% versus 21.2% [difference 69.2%; odds ratio (OR) = 48.4, 95% CI: 17.6-159.1]. Continued HAT treatment was also associated with an increasing proportion of patients without health problems and who had stopped illicit drug and excessive alcohol use: from 12% after the first year to 25% after 4 years of HAT. CONCLUSIONS: Long-term HAT is an effective treatment for chronic heroin addicts who have failed to benefit from methadone maintenance treatment. Four years of HAT is associated with stable physical, mental and social health and with absence of illicit heroin use and substantial reductions in cocaine use. HAT should be continued as long as there is no compelling reason to stop treatment.

Differential genetic regulation of motor activity and anxiety-related behaviors in mice using an automated home cage task.

Traditional behavioral tests, such as the open field test, measure an animal's responsiveness to a novel environment. However, it is generally difficult to assess whether the behavioral response obtained from these tests relates to the expression level of motor activity and/or to avoidance of anxiogenic areas. Here, an automated home cage environment for mice was designed to obtain independent measures of motor activity levels and of sheltered feeding preference during three consecutive days. Chronic treatment with the anxiolytic drug chlordiazepoxide (5 and 10 mg/kg/day) in C57BL/6J mice reduced sheltered feeding preference without altering motor activity levels. Furthermore, two distinct chromosome substitution strains, derived from C57BL/6J (host strain) and A/J (donor strain) inbred strains, expressed either increased sheltering preference in females (chromosome 15) or reduced motor activity levels in females and males (chromosome 1) when compared to C57BL/6J. Longitudinal behavioral monitoring revealed that these phenotypic differences maintained after adaptation to the home cage. Thus, by using new automated behavioral phenotyping approaches, behavior can be dissociated into distinct behavioral domains (e.g., anxiety-related and motor activity domains) with different underlying genetic origin and pharmacological responsiveness.

Assessment of cognitive brain function in ecstasy users and contributions of other drugs of abuse: results from an FMRI study.

Heavy ecstasy use has been associated with neurocognitive deficits in various behavioral and brain imaging studies. However, this association is not conclusive owing to the unavoidable confounding factor of polysubstance use. The present study, as part of the Netherlands XTC Toxicity study, investigated specific effects of ecstasy on working memory, attention, and associative memory, using functional magnetic resonance imaging (fMRI). A large sample (n=71) was carefully composed based on variation in the amount and type of drugs that were used. The sample included 33 heavy ecstasy users (mean 322 pills lifetime). Neurocognitive brain function in three domains: working memory, attention, and associative memory, was assessed with performance measures and fMRI. Independent effects of the use of ecstasy, amphetamine, cocaine, cannabis, alcohol, tobacco, and of gender and IQ were assessed and separated by means of multiple regression analyses. Use of ecstasy had no effect on working memory and attention, but drug use was associated with reduced associative memory performance. Multiple regression analysis showed that associative memory performance was affected by amphetamine much more than by ecstasy. Both drugs affected associative memory-related brain activity, but the effects were consistently in opposite directions, suggesting that different mechanisms are at play. This could be related to the different neurotransmitter systems these drugs predominantly act upon, that is, serotonin (ecstasy) vs dopamine (amphetamine) systems.

Patterns of acquisitive crime during methadone maintenance treatment among patients eligible for heroin assisted treatment.

OBJECTIVE: To determine the patterns of acquisitive crime during methadone maintenance treatment among chronic, treatment-resistant heroin users eligible for heroin assisted treatment in the Netherlands. METHODS: We retrospectively assessed the type and number of illegal activities during 1 month of standard methadone maintenance treatment in 51 patients prior to the start of heroin assisted treatment. Data were collected using a semi-structured interview focussed on crime with special emphasis on property crime. Volume analyses consisted of frequencies and descriptives of mean numbers of offences per day and per type. RESULTS: In a Dutch population of problematic drug users eligible for and prior to commencing heroin assisted treatment, 70% reported criminal activities and 50% reported acquisitive crimes. Offending took place on 20.5 days per month with on average 3.1 offences a day. Acquisitive crime consisted mainly of shoplifting (mean 12.8 days, 2.2 times/day) and theft of bicycles (mean 5.8 days, 2.4 times/day); theft from a vehicle and burglaries were committed less frequently. The majority of these patients (63%) reported to have started offending in order to acquire illicit drugs and alcohol. CONCLUSION: During methadone maintenance treatment, 50% of criminally active, problematic heroin users eligible for heroin assisted treatment reported acquisitive crime. Shoplifting, thefts and/or other property crimes were committed on average two to three times on a crime day. This study discusses that the detail provided by self-reported crime data can improve cost estimates in economic evaluations of heroin assisted treatment.

Screening for illicit heroin use in patients in a heroin-assisted treatment program.

The aim of this study was to investigate the use of illicit heroin among patients in a heroin-assisted treatment program. In this program, pharmaceutical-grade heroin was administered to heroin-addicted patients. Monitoring of illicit heroin use was considered important for the evaluation of this treatment program. Acetylcodeine and codeine, common adulterants of "street" heroin, were used as markers for illicit heroin. A liquid chromatography method with tandem mass spectrometric detection (LC-MS-MS) was developed, for quantitative analysis of heroin and methadone, their metabolites, and the simultaneous detection of acetylcodeine. One-hundred patients in a heroin-assisted treatment program were screened for acetylcodeine in plasma. Furthermore, patients were interviewed about illicit heroin use, and they were tested for alcohol and cocaine use. In plasma samples of 16% of the patients, acetylcodeine was detected. Overall agreement between self-report and plasma samples was 95% (kappa: 0.81). Patients who tested positive for acetylcodeine had visited the outpatients' clinics significantly less frequently than the patients who tested negative. Alcohol and cocaine use was more common in patients who tested positive for acetylcodeine. Illicit heroin use was observed in a limited percentage of patients. Overall agreement between self-report and markers of illicit heroin use was good.

Population pharmacokinetics of heroin and its major metabolites.

BACKGROUND: In several European countries and in Canada, clinical trials are being conducted in which heroin-addicted patients are treated with pharmaceutically prepared heroin in order to reduce the destructive behaviour that is so often associated with this drug. OBJECTIVE: To develop an integrated population pharmacokinetic model for heroin (diamorphine) and its pharmacodynamically active metabolites 6-acetylmorphine, morphine, morphine-3-glucuronide and morphine-6-glucuronide. Additionally, the influence on heroin pharmacokinetics of several covariates that are typical for this population was determined. METHOD: Plasma concentration data from 106 heroin-dependent patients in The Netherlands (74 heroin inhalers and 32 injectors) were obtained. The 'chasing the dragon' technique was used for inhalation, in which the fumes of heroin base, heated on aluminum foil, were inhaled. Heroin doses varied between 66 and 450 mg. Heroin, 6-acetylmorphine and morphine data were fitted simultaneously using sequential two-compartment models. Morphine-3-glucuronide and morphine-6-glucuronide data were fitted separately to one-compartment models. All data analysis was performed using nonlinear mixed-effect modelling. RESULTS: The bioavailability of inhaled heroin was estimated to be 53% (95% CI 43.7, 62.3). The terminal half-lives of heroin and 6-acetylmorphine were estimated to be 7.6 and 21.8 minutes, respectively. The clearances of morphine and the morphine-glucuronides were estimated to be 73.6 L/h (95% CI 62.8, 84.4) and between 6 and 10 L/h, respectively. The terminal half-life of 6-acetylmorphine was 13% lower in cocaine users (p < 0.05). No other significant relationships between covariates and pharmacokinetic parameters were discovered. CONCLUSIONS: Pharmacokinetic parameters of heroin and its five major metabolites were assessed simultaneously in one integrated model. Covariate analyses revealed that sex, bodyweight, benzodiazepine use and creatinine clearance (>60 mL/min) do not need to be taken into account in the medical prescription of pharmaceutically prepared heroin for the treatment of heroin dependency.

Analysis of diacetylmorphine, caffeine, and degradation products after volatilization of pharmaceutical heroin for inhalation.

Pharmaceutical smokable heroin was developed for a clinical trial on medical co-prescription of heroin and methadone. This product, consisting of 75% w/w diacetylmorphine base and 25% w/w caffeine anhydrate, was intended for use via "chasing the dragon", that is, inhalation after volatilization. This procedure involves heating the powder mixture, which may lead to formation of degradation products that could subsequently be inhaled. We developed a method that used a high-performance liquid chromatography system that was compatible with photodiode-array detection and mass spectrometric detection to separate diacetylmorphine- and caffeine-related compounds in a wide polarity range for analysis of the vapor. This method was used to analyze the contents of the plastic drinking straws that were used by patients to inhale the vapors from pharmaceutical heroin used via chasing the dragon, which were considered to be representative of the vapors the patients inhaled. They contained primarily unchanged diacetylmorphine, its main metabolite 6-acetylmorphine, caffeine, and some morphine. Several unidentified peaks were observed in the straw chromatograms. Chemical structures were proposed for nine degradation products: morphine derivatives with different substitution patterns of the C(3), C(6), and/or N(17) positions, which comprised 0.4-9.7% of the straw sample residue weight. Activity and toxicity of most of these compounds are unknown and require further investigation.

Validity of the EQ-5D as a generic health outcome instrument in a heroin-dependent population.

OBJECTIVE: To evaluate the validity of the EuroQol (EQ-5D) in a population of chronic, treatment-resistant heroin-dependent patients. METHODS: The EQ-5D is studied relative to the Maudsley Addiction Profile (MAP), the Symptom Checklist (SCL-90) and the European Addiction Severity Index (EuropASI) which were used to assess the participant's physical functioning, mental health and social integration, respectively. Data were gathered from 430 patients participating in the Dutch heroin trials with an intended 12-month treatment period. The EQ-5D was used as a separate health outcome measure. Statistical analyses were conducted using Spearman's and Pearson's correlations. RESULTS: The EQ-5D dimensions mobility, self-care and usual activities generally showed low correlations with relevant parameters of the MAP-HSS, SCL-90 and EuropASI (r=0.132-0.369). The EQ-5D dimension pain/discomfort showed low to moderate hypothesized correlations with all disease-specific measures (r=0.153-0.496). The EQ-5D dimension anxiety/depression showed moderate to high correlations with the SCL-90 (including the sum score) and some of the EuropASI parameters (r=0.133-0.615). The EQ-5D utility scores were moderately correlated with the MAP-HSS (r=-0.468) and the SCL-90 (r=-0.491) total score and with response to treatment at month 12. CONCLUSION: The majority of hypothesized associations between the EQ-5D and the disease or domain-specific measures could be confirmed. The validity of the EQ-5D-based utility score appears to be suitable in the evaluation of chronic, heroin-dependent populations.

Deuterodiacetylmorphine as a marker for use of illicit heroin by addicts in a heroin-assisted treatment program.

In preparation for a treatment program concerning the medical coprescription of heroin and methadone to treatment-resistant addicts in the Netherlands, we studied a novel strategy for monitoring co-use of illicit (nonprescribed) heroin. A deuterated analogue of heroin was added (1:20) to pharmaceutical, smokable heroin (a powder mixture of 75% w/w diacetylmorphine base and 25% w/w caffeine anhydrate), to be used by inhalation after volatilization ("chasing the dragon"). Plasma and urine samples were collected from nine male patients who had used pharmaceutical, smokable heroin during a four-day stay in a closed clinical research unit, and these samples were analyzed by liquid chromatography coupled with tandem mass spectrometry. Ratios of deuterated and undeuterated diacetylmorphine and 6-acetylmorphine (MAM/MAM-d3) in plasma and urine were calculated from peak areas of these substances in the respective chromatograms. The MAM/MAM-d3 ratios in plasma and urine were normally distributed (with small standard deviations) and independent from concentrations of 6-acetylmorphine and from time after use of pharmaceutical heroin. A MAM/MAM-d3 ratio in urine above 32.8 was considered indicative of co-use of illicit heroin, and this value was associated with a false-positive rate of only 1% (95% confidence interval: -1 to 3%). The MAM/MAM-d3 ratio was detectable in urine for 4-9.5 h after use of pharmaceutical, smokable heroin. Addition of stable, isotopically labelled heroin to pharmaceutical, smokable heroin is considered to be a feasible strategy for the detection of co-use of illicit heroin by patients in heroin-assisted treatment.

The quantitative analysis of heroin, methadone and their metabolites and the simultaneous detection of cocaine, acetylcodeine and their metabolites in human plasma by high-performance liquid chromatography coupled with tandem mass spectrometry.

For a pharmacokinetic-pharmacodynamic study in opioid tolerant patients, who were treated with heroin in combination with methadone, a liquid chromatographic assay with tandem mass spectrometry detection (LC-MS/MS) was developed for the simultaneous determination of heroin, methadone, heroin metabolites 6-monoacetylmorphine, morphine, and morphine-6 and 3-glucuronide and methadone metabolite EMDP. To detect any abuse of substances besides the prescribed opioids the assay was extended with the detection of cocaine, its metabolites benzoylecgonine and norcocaine and illicit heroin adulterants acetylcodeine and codeine. Heroin-d6, morphine-d3, morphine-3-glucuronide-d3 and methadone-d9 were used as internal standards. The sample pre-treatment consisted of solid phase extraction using mixed mode sorbent columns (MCX Oasis). Chromatographic separation was performed at 25 degrees C on a reversed phase Zorbax column with a gradient mobile phase consisting of ammonium formate (pH 4.0) and acetonitrile. The run time was 15 min. MS with relatively mild electrospray ionisation under atmospheric pressure was applied. The triple quadrupole MS was operating in the positive ion mode and multiple reaction monitoring (MRM) was used for drug quantification. The method was validated over a concentration range of 5-500 ng/mL for all analytes. The total recovery of heroin varied between 86 and 96% and of the heroin metabolites between 76 and 101%. Intra-assay and inter-assay accuracy and precision of all analytes were always within the designated limits (< or =20% at lower limit of quantification (LLQ) and < or =15% for other samples). This specific and sensitive assay was successfully applied in pharmacokinetic studies with medically prescribed heroin and toxicological cases.

Cost utility analysis of co-prescribed heroin compared with methadone maintenance treatment in heroin addicts in two randomised trials.

OBJECTIVE: To determine the cost utility of medical co-prescription of heroin compared with methadone maintenance treatment for chronic, treatment resistant heroin addicts. DESIGN: Cost utility analysis of two pooled open label randomised controlled trials. SETTING: Methadone maintenance programmes in six cities in the Netherlands. PARTICIPANTS: 430 heroin addicts. INTERVENTIONS: Inhalable or injectable heroin prescribed over 12 months. Methadone (maximum 150 mg a day) plus heroin (maximum 1000 mg a day) compared with methadone alone (maximum 150 mg a day). Psychosocial treatment was offered throughout. MAIN OUTCOME MEASURES: One year costs estimated from a societal perspective. Quality adjusted life years (QALYs) based on responses to the EuroQol EQ-5D at baseline and during the treatment period. RESULTS: Co-prescription of heroin was associated with 0.058 more QALYs per patient per year (95% confidence interval 0.016 to 0.099) and a mean saving of 12,793 euros (8793 pounds sterling, 16,122 dollars) (1083 to 25,229 euros) per patient per year. The higher programme costs (16 222 euros; lower 95% confidence limit 15,084 euros) were compensated for by lower costs of law enforcement (- 4129 euros; upper 95% confidence limit - 486 euros) and damage to victims of crime (- 25,374 euros; upper 95% confidence limit - 16,625 euros). The results were robust for the use of national EQ-5D tariffs and for the exclusion of the initial implementation costs of heroin treatment. Completion of treatment is essential; having participated in any abstinence treatment in the past is not. CONCLUSIONS: Co-prescription of heroin is cost effective compared with treatment with methadone alone for chronic, treatment resistant heroin addicts.

Pharmacokinetic comparison of two methods of heroin smoking: 'chasing the dragon' versus the use of a heating device.

In preparation for a trial on co-prescription of inhalable heroin and methadone, two methods for inhalation of heroin/caffeine tablets were compared: the commonly used method of 'chasing the dragon' and a standardised procedure for inhalation of volatilised heroin, using a heating device. Five male addicts inhaled a tablet of smokable heroin daily for 5 days, alternating the inhalation method. Plasma concentrations of heroin, 6-acetylmorphine, morphine and morphine-3- and -6-glucuronide were determined using a liquid chromatography method with tandem mass spectrometric detection. The exposure to heroin and its metabolites (expressed as areas under the concentration-time curve) was significantly lower after smoking via the heating device than after 'chasing the dragon': heroin 80% and 6-acetylmorphine 73% lower (p < 0.05). Maximal concentrations of heroin and 6-acetylmorphine were also 80% and 70% lower (p < 0.05) after using the heating device. 'Chasing the dragon' is a more efficient inhalation method than inhalation via the heating device.

Population pharmacokinetics of caffeine and its metabolites theobromine, paraxanthine and theophylline after inhalation in combination with diacetylmorphine.

The stimulant effect of caffeine, as an additive in diacetylmorphine preparations for study purposes, may interfere with the pharmacodynamic effects of diacetylmorphine. In order to obtain insight into the pharmacology of caffeine after inhalation in heroin users, the pharmacokinetics of caffeine and its dimethylxanthine metabolites were studied. The objectives were to establish the population pharmacokinetics under these exceptional circumstances and to compare the results to published data regarding intravenous and oral administration in healthy volunteers. Diacetylmorphine preparations containing 100 mg of caffeine were used by 10 persons by inhalation. Plasma concentrations of caffeine, theobromine, paraxanthine and theophylline were measured by high performance liquid chromatography. Non-linear mixed effects modelling was used to estimate population pharmacokinetic parameters. The model was evaluated by the jack-knife procedure. Caffeine was rapidly and effectively absorbed after inhalation. Population pharmacokinetics of caffeine and its dimethylxanthine metabolites could adequately and simultaneously be described by a linear multi-compartment model. The volume of distribution for the central compartment was estimated to be 45.7 l and the apparent elimination rate constant of caffeine at 8 hr after inhalation was 0.150 hr(-1) for a typical individual. The bioavailability was approximately 60%. The presented model adequately describes the population pharmacokinetics of caffeine and its dimethylxanthine metabolites after inhalation of the caffeine sublimate of a 100 mg tablet. Validation proved the stability of the model. Pharmacokinetics of caffeine after inhalation and intravenous administration are to a large extent similar. The bioavailability of inhaled caffeine is approximately 60% in experienced smokers.