Calcium channel blocking drugs in the management of drug dependence, withdrawal and craving. A clinical pilot study with nifedipine and verapamil

Abstract

Objective: To determine if the calcium channel blocking agents (CCBs), nifedipine and verapamil are safe and effective therapeutic adjuncts in the management of withdrawal and craving in patients with chronic dependence on opiates, ethanol, amphetamine, benzodiazepines and marijuana.

Method: Oral rapid acting nifedipine or verapamil was administered for 2 weeks (together with oral methadone in decreasing daily doses and specific symptomatic treatment, if appropriate), to patients with chronic dependence on various drugs of addiction. Several objective and subjective parameters were quantified to provide information about the patient's basic condition and progressive response to treatment, both before and after each CCB treatment. Patients also completed a daily questionnaire concerning their withdrawal intensity and provided a daily urine analysis.

Results: Both nifedipine and verapamil appeared to be safe and effective therapeutic adjuncts in the management of withdrawal and craving in 24 patients who successfully completed the trial. Although comparable in therapeutic efficacy in the doses used, verapamil produced far fewer and milder side effects than nifedipine. None of the verapamil side effects resulted in suspension or termination of treatment and it was the preferred agent, especially in patients presenting with a low blood pressure.

Conclusions: In this pilot study nifedipine and verapamil appeared to be effective for the in-patient management of withdrawal and craving in a broad spectrum of chronic drug addicts. Verapamil produced fewer disturbing side effects compared with nifedipine and it may prove a safe, non-addicting and rational treatment in the long term management of chronic dependence, withdrawal and craving. As such, it may be especially valuable in offering the motivated chronic addict help and hope for the long term management of this problem in a community setting. The present results warrant the establishment of a verapamil based, double-blind, drug-matched or placebo-controlled clinical trial to test the validity and significance of these preliminary findings.