ENHANCEMENT OF OPIATE ANALGESIA BY NIMODIPINE IN CANCER-PATIENTS CHRONICALLY TREATED WITH MORPHINE - A PRELIMINARY-REPORT

The ability of nimodipine, a calcium-channel blocker, to enhance morph ine analgesia and/or modify the development of tolerance was studied i n patients with cancer pain who had needed successive increments of mo rphine for periods ranging from 21 to 780 days. Assessment of daily mo rphine consumption was the primary effect parameter. Nimodipine succee ded in reducing the daily dose of morphine in 16 of 23 patients (oral, n = 13; intrathecal, n = 3), and failed to modify it in 2 patients. T otal oral daily dose was reduced by nimodipine (120 mg/day) from 282.6 +/- 47.7 mg to 158.7 +/- 26.2 mg (n = 15, P < 0.001). Intrathecal mor phine was also reduced by 1-5 mg/day. Nimodipine was withdrawn in 5 pa tients during the first week of treatment due to intolerance (n = 3) o r aggravation of the disease (n = 2). These preliminary results suppor t experimental findings showing that pharmacological interference with Ca2+-related events may modify chronic opioid effects, including the expression of tolerance.