title: Sustained-release dexamfetamine in the treatment of chronic cocaine-dependent patients on heroin-assisted treatment: a randomised, double-blind, placebo-controlled trial.
abstract: BACKGROUND
  Heroin-assisted treatment is effective for methadone treatment-refractory heroin-dependent patients, but continued comorbid cocaine dependence remains problematic. Sustained-release dexamfetamine is a promising agonist pharmacotherapy for cocaine dependence and we aimed to assess its acceptance, efficacy, and safety.
  
  
  METHODS
  In this multicentre, randomised, double-blind, placebo-controlled trial, patients who were treatment-refractory, as indicated by at least two earlier failed treatments aimed at reducing or abstaining from cocaine use, and who regularly (≥8 days/month) used crack-cocaine were enrolled from four heroin-assisted treatment centres in the Netherlands. Eligible patients were randomly assigned (1:1) to receive either 12 weeks of daily, supervised prescription of 60 mg/day oral sustained-release dexamfetamine or placebo in addition to co-prescribed methadone and diacetylmorphine. Randomisation was done by the collaborating pharmacist, using a computer-generated random number sequence with stratification by treatment centre in blocks of four per stratum. Randomisation was masked to patients, staff, and researchers throughout the study. The primary outcome was the number of self-reported days of cocaine use during study treatment, assessed every 4 weeks. Primary and safety analyses were done in the intention-to-treat population. The study was registered with the European Union Drug Regulating Authorities Clinical Trials (EUdraCT 2013-004024-11) and with The Netherlands Trial Register (NTR2576).
  
  
  RESULTS
  Between Aug 8, 2014, and Feb 27, 2015, 111 patients were assessed for eligibility, of whom 73 were enrolled and randomised; 38 patients were assigned to the sustained-release dexamfetamine group and 35 to the placebo group. Sustained-release dexamfetamine treatment resulted in significantly fewer days of cocaine use than placebo treatment (mean 44·9 days [SD 29·4] vs 60·6 days [24·3], respectively [95% CI of difference 3·1-28·4]; p=0·031; Cohen's standardised effect size d=0·58). One or more adverse events were reported by 28 (74%) patients in the dexamfetamine group and by 16 (46%) patients in the placebo group. Most adverse events were transient and well-tolerated.
  
  
  CONCLUSIONS
  Sustained-release dexamfetamine is a well accepted, effective, and safe agonist pharmacotherapy for comorbid treatment-refractory cocaine dependence in heroin-dependent patients in heroin-assisted treatment. Future research should aim to replicate these findings in chronic cocaine-dependent and other stimulant-dependent patients in more routine treatment settings, including strategies to optimise treatment adherence like medication management interventions and contingency management.
  
  
  BACKGROUND
  Netherlands Organisation for Health Research and Development.
authors.affiliation: Parnassia Addiction Research Centre (PARC, Brijder Addiction Treatment), The Hague, Netherlands. Electronic address: mascha.nuijten@brijder.nl.
authors.forename: Mascha
authors.initials: M
authors.lastname: Nuijten
authors.affiliation: Parnassia Addiction Research Centre (PARC, Brijder Addiction Treatment), The Hague, Netherlands.
authors.forename: Peter
authors.initials: P
authors.lastname: Blanken
authors.affiliation: Antes Group, Bouman, Rotterdam, Netherlands.
authors.forename: Ben
authors.initials: B
authors.lastname: van de Wetering
authors.affiliation: Antoni van Leeuwenhoek/The Netherlands Cancer Institute, Medical Centre Slotervaart, Amsterdam, Netherlands.
authors.forename: Bastiaan
authors.initials: B
authors.lastname: Nuijen
authors.affiliation: Amsterdam Institute for Addiction Research, Department of Psychiatry, Academic Medical Centre, University of Amsterdam, Amsterdam, Netherlands.
authors.forename: Wim
authors.initials: W
authors.lastname: van den Brink
authors.affiliation: Parnassia Addiction Research Centre (PARC, Brijder Addiction Treatment), The Hague, Netherlands; Curium, Leiden University Medical Centre, Department of Child and Adolescent Psychiatry, Leiden University, Leiden, Netherlands.
authors.forename: Vincent M
authors.initials: VM
authors.lastname: Hendriks
mesh_terms: D000284:Administration, Oral; D000697:Central Nervous System Stimulants / Q000008:administration & dosage* / Q000009:adverse effects; D002908:Chronic Disease; D019970:Cocaine-Related Disorders / Q000534:rehabilitation*; D016578:Crack Cocaine; D003692:Delayed-Action Preparations; D003913:Dextroamphetamine / Q000008:administration & dosage* / Q000009:adverse effects; D004311:Double-Blind Method; D005260:Female; D006556:Heroin Dependence / Q000534:rehabilitation; D006801:Humans; D008297:Male; D008875:Middle Aged; D010342:Patient Acceptance of Health Care; D016896:Treatment Outcome
chemical_list: D000697:Central Nervous System Stimulants; D016578:Crack Cocaine; D003692:Delayed-Action Preparations; D003913:Dextroamphetamine