Studies in animals and humans have demonstrated that clonidine hydrochloride, an alpha-2-noradrenergic agonist, significantly attenuates the opiate withdrawal syndrome. Inpatient and outpatient clinical studies have shown that clonidine is a reasonably safe, specific, and effective agent for detoxifying opiate addicts. Clonidine seems best suited for use as a transitional treatment between opiate dependence and induction onto the opiate antagonist naltrexone. Dosage regimens of clonidine must be individualized according to symptoms and side effects and closely supervised because of varying sensitivity to clonidine's sedative, hypotensive, and withdrawal-suppressing effects. Clonidine is an important new treatment option for selected opiate addicts and may be the treatment of choice when detoxification using methadone is inappropriate, unsuccessful, or unavailable. Lofexidine, a structural analogue of clonidine, may be safer and more effective as an opiate detoxification treatment. It has similar withdrawal-suppressing actions but causes little hypotension and sedation. Although clonidine and lofexidine may be highly effective in helping opiate addicts achieve initial abstinence, a multi-modality aftercare treatment approach including naltrexone and psychotherapy may be necessary to maintain an abstinent state.