title: The effects of racemic D,L-methadone and L-methadone in substituted patients--a randomized controlled study.
abstract: OBJECTIVE
  To test the hypothesis that switching from L-methadone to D,L-methadone is associated with more frequent withdrawal symptoms and side-effects than switching from D,L-methadone to L-methadone.
  
  
  METHODS
  Stratified, randomized 2 x 2 crossover study design over a time-period of 8 weeks. At study entry, every second patient was switched from the pre-study substance to the other medication, after 4 weeks all patients were subject to a (re-)switch.
  
  
  METHODS
  The study was conducted as a multi-centre trial in three methadone maintenance therapy (MMT) clinics.
  
  
  METHODS
  Seventy-five patients previously treated with either D,L-methadone or L-methadone for at least 1 year took part in the study.
  
  
  METHODS
  Intra-individual changes in withdrawal symptoms (Short Opiate Withdrawal Scale, SOWS) and side-effects were defined as primary outcome criteria. Secondary outcome measures included necessity for methadone dose adjustment.
  
  
  RESULTS
  Complete data were available for 68 patients (91%). Sample strata were unbalanced at baseline: 15 patients (22%) were treated with L-methadone and 43 with D,L-methadone (78%). Thirty-five patients were randomized into the group treated with L-methadone and 33 into the group treated with D,L-methadone during the first 4 weeks. There were no significant differences in intra-individual change of withdrawal symptoms and side-effects between groups after crossover. However, patients treated with levomethadone tended to feel less withdrawal symptoms than patients treated with d,l-methadone.
  
  
  CONCLUSIONS
  D,L-methadone and L-methadone can safely be replaced by each other on a 2:1 ratio. Withdrawal symptoms or side-effects due to conversion are of transient nature only.
authors.affiliation: Centre for Interdisciplinary Addiction Research, University of Hamburg, Martinistr. 52, D-20246 Hamburg, Germany. verthein@sozialwiss.uni-hamburg.de
authors.forename: Uwe
authors.initials: U
authors.lastname: Verthein
authors.forename: Rainer
authors.initials: R
authors.lastname: Ullmann
authors.forename: Anke
authors.initials: A
authors.lastname: Lachmann
authors.forename: Andreas
authors.initials: A
authors.lastname: Düring
authors.forename: Barbara
authors.initials: B
authors.lastname: Koch
authors.forename: Hans-Günter
authors.initials: HG
authors.lastname: Meyer-Thompson
authors.forename: Rolf
authors.initials: R
authors.lastname: Schmidt
authors.forename: Jens
authors.initials: J
authors.lastname: Reimer
authors.forename: Christian
authors.initials: C
authors.lastname: Haasen
mesh_terms: D000328:Adult; D018592:Cross-Over Studies; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008297:Male; D008691:Methadone / Q000031:analogs & derivatives* / Q000627:therapeutic use*; D009294:Narcotics / Q000627:therapeutic use*; D009293:Opioid-Related Disorders / Q000534:rehabilitation*
chemical_list: D009294:Narcotics; D008691:Methadone