Levomethadyl acetate is an
orally active methadone derivative with a slow
onset and a long duration of action. The compound
is extensively metabolized and active
metabolites contribute to the long duration of
action. Levomethadyl acetate was used mainly
for substitution treatment of opioid dependence
. Oral doses from 20 up to 140 mgare given
every 2–3 d. Supplementation with short acting
opioids is necessary during the first days because
of the delayed onset of action.
Levomethadyl acetate induces opioid-type
side effects with respiratory depression, bradycardia,
and impairment of cardiac contractility
. The compound inhibits cardiac electric
conductivity and increases the QT interval
in the electrocardiogram and may induce
ventricular arrhythmias and Torsade de pointes
. Because of the cardiovascular side effects (Q/T-interval prolongation), the compound was
recently withdrawn from the market.
