Clinical toxicity of reserpine in hospitalized patients: a report from the Boston Collaborative Drug Surveillance Program.

Adverse reactions to reserpine were studied in 231 hospitalized medical patients who received the drug. Reserpine was administered specifically for hypertension in 91.3 percent of patients; 35.5 per cent of patients received the drug by intramuscular (IM) injection. The IM route of administration was associated with higher mean daily doses (1.28 +/- 0.14 mg/day) than was oral administration (0.37 +/- 0.02 mg/day). Adverse reactions to reserpine were reported in 26 patients (11.3 per cent), but only three of these reactions were considered life-threatening and no deaths were attributed to the drug. Central nervous system (CNS) disturbances, reported in 12 patients, were the most common unwanted effects. Gastrointestinal disturbances were reported in six patients, and hypotension in six. Toxicity occurred more frequently in those who received IM, and therefore high-dose, reserpine. Adverse reactions also were more common in patients who had not received rauwolfia derivatives prior to admission; however, this group of patients also received IM reserpine more frequently. Finally, reserpine toxicity, in particular central nervous system (CNS) disturbances, was reported more frequently in patients also receiving barbiturates, suggesting additive CNS effects.