Thrice-weekly dosing with the opioid agonists buprenorphine and levacetylmethadol
(LAAM) is effective in treating patients addicted to heroin and makes either
drug an attractive alternative to daily methadone, an American study suggests.
Researchers led by Dr Rolley Johnson
(department of psychiatry and behavioural sciences, Johns Hopkins university
school of medicine) compared the two drugs with high- and low-dose methadone
in a 17-week randomised, four-arm trial (55 heroin-addicted patients per arm).
All three drugs were found to reduce illicit opioid use effectively, say the
researchers.
Opioid-positive urine specimens decreased most in patients treated with LAAM
and least in patients taking low-dose methadone. The percentage of patients
with 12 or more consecutive opioid-negative urine specimens was highest in the
LAAM group (36 per cent) and lowest in the low-dose methadone group (8 per cent).
High-dose methadone takers were most likely to remain in the study, completing
an average of 105 out of a possible 119 days in the study. LAAM patients were
more likely to drop out of the study initially (mean retention 89 days), but
the patients who did stay were abstinent for longer. Thrice-weekly dosing of
buprenorphine was similar to LAAM in terms of retention and to high-dose methadone
in terms of abstinence.
The researchers comment that the higher effectiveness of LAAM during maintenance
may reflect more stable blood levels, with less variation in trough-to-peak
concentrations. The high drop out rate in this group may, in part, be explained
by the longer time required to achieve the targeted maintenance dose when compared
with methadone, they add.
LAAM and buprenorphine were administered thrice weekly, with placebo on intervening
days. High- and low-dose methadone were administered daily. Dosing was individualised
for all patients except those receiving low-dose (20mg) methadone, which served
as a control.
Dr Johnson and colleagues conclude that the three drugs yielded similar positive
outcomes (at individually optimised doses) and that the convenience and efficiency
of thrice-weekly dosing may make LAAM and buprenophine attractive options for
treatment of opioid addiction.
Mr David Thomson (director of pharmacy, Greater Glasgow primary care trust)
told The Journal on October 31 that, within his trust, LAAM and buprenorphine
were not widely used. However, he hoped to see an increased number of opioid-addicted
patients using the support mechanisms that were in place and, to facilitate
this, alternative treatments were likely to be needed.
Mr Thomson pointed out that there were
issues surrounding the potential for abuse of the two drugs and the logistics
of administering LAAM. Once these issues had been addressed then LAAM and buprenorphine
could well complement the current methadone service, he said.
The study is published in the New England Journal of Medicine (2000;343:1290).