To the Editor.—
The report from the Hypertensive Detection and Follow-up Program (HDFP) found that adverse drug reactions (ADRs) to antihypertensive drugs were infrequent.1 We recently completed a prospective study of ADRs in 1026 outpatients in a university teaching hospital. Using intensive surveillance for ADRs and a standardized method for assessing causality, we found that reactions to prescription drugs occurred in 3% to 5% of patients receiving new prescriptions. They were usually mild in their effects and nearly always reversible.2 We examined in detail drugs used for lowering blood pressure and found that they were similarly well tolerated.
Patients of six board-certified internists were enrolled for one calendar year. One third of the 1026 participants had hypertension. Surveillance for ADRs was carried out by frequent telephone calls at regular intervals. Any suspected ADRs were scored, according to a published algorithm,3 to establish a likelihood score. Each