Restabilization with methadone after methadyl acetate maintenance.

Sixty-eight heroin addicts maintained for 40 weeks on a regimen of methadyl acetate or methadone hydrochloride in a double-blind study were transferred to a uniform dose of 60 mg of methadone daily at the end of their tenure in the study. They were observed for the ensuing six weeks, during which their daily methadone doses were adjusted according to their clinical needs. Patients were observed for symptoms and signs of discomfort and for the amount of illicit drug use during this period of transition. The results indicate that patients maintained on a regimen of methadyl acetate can be readily restabilized with methadone and that sudden decrease of the methadone dose tends to result in the patient's supplementing with illicit heroin. Conversely, increasing methadone doses resulted in a corresponding reduction in illicit drug use. It is suggested that a chronic covert abstinence syndrome may exist in some patients receiving long-term methadone maintenance therapy, and that while it may contribute to their continued illicit drug use, it may have a different pathophysiologic basis and require different therapeutic considerations.