Effects of short‐ and long‐term administration of pentazocine in man

Pentazocine produces morphine‐like subjective effects. A dose of 60 mg. per 70 Kg. produces subjective effects which more closely resemble those of nalorphine than those of morphine. Pentazocine will not suppress abstinence symptoms in subjects dependent on either 60 or 240 mg. per day of morphine. Pentazocine is 1/50 as potent as nalorphine in precipitating abstinence symptoms in subiects dependent on 240 mg. of morphine per day. Long‐term administration of pentazocine produces dependence which has elements of both morphine and nalorphine dependence. It is concluded that pentazocine has an abuse potential which is less than that with morphine but greater than that with nalorphine.