Prospective trial on captopril-related cough

OBJECTIVE: Quantify and characterize cough as an adverse reaction secondary to captopril. DESIGN: Cohort analytic study: six-month prospective trial including two-week, placebo, run-in period; five-month, single-blind, active treatment; and two-week, dechallenge period. SETTING: Outpatient clinic. PATIENTS: 199 previously treated or newly diagnosed untreated patients with mild to moderate hypertension. INTERVENTIONS: Captopril 50 mg/d during five months. OUTCOME MEASURES: Self-questionnaires, interviews, dechallenge, and rechallenge periods. Naranjo's algorithm. RESULTS AND CONCLUSIONS: (1) Cumulative incidence of captopril-induced cough over a five-month period was 7.1 percent (95 percent C.I., 6.8-7.4 percent). Incidence of drug withdrawal secondary to severe cough was 1.0 percent; this figure is somewhat similar to first reports about the reaction. (2) Cough was a generally mild to moderate symptom, present day and night in 71.4 percent of patients and resistant to antitussive agents. Cough was not statistically related to sex, age, or smoking habit; however, the female gender and the development of a common cold may be predisposing factors.