The effects of racemic D,L-methadone and L-methadone in substituted patients--a randomized controlled study.
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.
Verthein
Uwe
U
Centre for Interdisciplinary Addiction Research, University of Hamburg, Martinistr. 52, D-20246 Hamburg, Germany. verthein@sozialwiss.uni-hamburg.de
Ullmann
Rainer
R
Lachmann
Anke
A
Düring
Andreas
A
Koch
Barbara
B
Meyer-Thompson
Hans-Günter
HG
Schmidt
Rolf
R
Reimer
Jens
J
Haasen
Christian
C
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*
D009294:Narcotics; D008691:Methadone