A controlled comparison of clonidine and doxepin in the treatment of the opiate withdrawal syndrome.

Clonidine and doxepin alleviate the symptoms of the opiate withdrawal syndrome. Clonidine was slightly more effective in controlling sweating, hot flushes, palpitations and nausea, and doxepin was slightly more effective in relieving the craving for opiates, lassitude and depression. Adverse effects such as sedation, dry mouth and falls in blood pressure occurred in both groups. There were six cases of collapse during treatment with high doses of doxepin, whereas only one subjective circulatory effect occurred in the clonidine group. At these high doses, doxepin may cause orthostatic hypotension via a peripheral alpha-receptor blockade. Clonidine reduced pulse rate whereas doxepin, with its anticholinergic action and indirectly via its alpha-receptor blocking action, raised it. Several patients in the doxepin group hat fits, as opposed to only one in the clonidine group. It is possible that the use of barbiturates had reduced the convulsive threshold in some of our patients. Overall, clonidine and doxepin were equipotent at adequate individual dose levels, and both were well tolerated. In this trial, serious side-effects occurred less often in the clonidine group.