Pharmacologic Interventions for the Treatment of Opioid Dependence and Withdrawal

Abstract

This article discusses current pharmacologic methods in the treatment of heroin dependence and withdrawal. Methadone hydrochloride, the most commonly used opiate agonist, is used for both withdrawal and maintenance therapy. However, it produces dependence and withdrawal results upon abrupt discontinuation. Other opiate agonists including l-alpha acetyl methadyl (LAAM) and propoxyphene napsylate have been used for both withdrawal and maintenance therapy. LAAM is currently available only as an investigational agent and propoxyphene is easily accessible but has been associated with hallucinations and dysphoria at high doses. Alpha₂-adrenergic agonists decrease opiate withdrawal symptoms by decreasing the central adrenergic hyperarousal that is associated with withdrawal. Clonidine effectively attenuates but does not totally eliminate withdrawal symptoms. Other alpha₂-adrenergic agonists (e.g., lofexidine hydrochloride, guanfacine hydrochloride, and guanabenz) have undergone only preliminary investigations. Although alpha₂ agonists effectively decrease most withdrawal symptoms they often cause hypotension. Buprenorphine hydrochloride is a partial opiate agonist that shows some promise in the treatment of the heroin-dependent population. It attenuates opiate craving and causes only minimal withdrawal upon abrupt discontinuation. Because it is well accepted by the heroin-dependent population, however, it may ultimately become an abused substance. Naltrexone is a potent, orally acting opiate antagonist that blocks all opiate-agonist effects and causes no euphoria. Unfortunately, it has not been well accepted by the heroin-dependent population. Scant research has been conducted concerning the use of adjunctive medications during opioid withdrawal.