THE EFFECTS OF LEVO-ALPHA-ACETYLMETHADOL AND ITS METABOLITES ON SCHEDULE-CONTROLLED BEHAVIOR IN THE PIGEON

  • 1 January 1981
    • journal article
    • research article
    • Vol. 216  (2) , 299-305
Abstract
Levo-.alpha.-acetylmethadol (LAAM) is currently being examined as an alternative to methadone in the maintenance treatment of opioid addiction in man. The effects of orally administered LAAM on the schedule-controlled behavior of the pigeon were compared with those of methadone. Both LAAM and methadone decreased rates of responding under a multiple fixed-interval 5 min, fixed-ratio 30 response schedule of food presentation. LAAM had a longer duration of action than methadone, but both drugs were similar in the onset and potency of their behavioral effects. The chronic administration of LAAM or methadone produced tolerance to the respective behavioral effects of each drug. In 1 set of experiments, the behavioral effects of administered LAAM were compared with those of its active metabolites, levo-.alpha.-noracetylmethadol and levo-.alpha.-dinoracetylmethadol. All 3 drugs decreased rates of responding under both components of the multiple schedule. The onset of the rate-decreasing effects was rapid and the order of potency for the production of these rate-decreases was levo-.alpha.-noracetylmethadol > levo-.alpha.-dinoracetylmethadol .gtoreq. LAAM. The rate-decreasing effects of LAAM and its metabolites were typical narcotic effects as defined by their reversal by naloxone.