Effect of sulpiride on chronic abstinence syndrome in addicted patients.

A total of 410 patients (342 men and 68 women) addicted to heroin for at least 38 months, with or without previous methadone treatment experience, were treated with sulpiride before the appearance of withdrawal syndrome. The drug was injected intramuscularly in a single administration at a dosage of 600 mg. Successively, sulpiride was injected intramuscularly at a dosage of 200 mg 3 times per day from days 2-21 of hospitalization, and then at a dosage of 100 and 50 mg 3 times per day (days 22-25 and 26-29, respectively). All patients showed a suppression of withdrawal signs and symptoms within 6 days of treatment, as assessed by subjective and objective scores. The effect of sulpiride was compared with that of placebo administered to a control group of 10 heroin addicts. Because prolactin has been shown to reduce the dependence of rats to heroin and the naloxone-precipitated withdrawal syndrome in morphine-addicted animals, the effects of sulpiride on heroin addiction may be related to the hyperprolactinemic action of this drug.