Dechallenge and rechallenge method showed different incidences of cough among four ACE-Is

To determine the incidence of cough secondary to (1) Cilazapril, (2) Enalapril, (3) Imidapril, and (4) Perindopril and their efficacy in the control of hypertension.

Randomized double-blind study conducted in selected medical centers in the Philippines from the first quarter of 1999 to March, 2001.

A total of 301 patients, aged 28-86 years with stage I or II hypertension were included. Patients were randomized to Cilazapril 2.5-5.0 mg/day (n=70), Enalapril 10-20 mg/day (n=82), Perindoril 4-8 mg/day (n=73), or Imidapril 10-20 mg/day (n=76). Hydrochlorothiazide 12.5 mg/day was added if needed. Using a dechallenge and rechallenge method, a strict criteria to attribute cough to angiotensin converting enzyme inhibitors (ACE-Is) not yet used in previous reports, the cough incidence were as follows: (1) Cilazapril--22.86% (16/70), (2) Enalapril--21.95% (18/82), (3) Perindopril--10.96% (6/73), and (4) Imidapril--13.16% (10/76) (P=0.041). Control of hypertension was significantly better with Enalapril during the first follow-up period.

Statistically significant differences in the incidence of cough among the studied ACE-Is were noted. Control of hypertension was observed to be better in those with a higher incidence of cough; however, the mean change of both systolic and diastolic blood pressure levels were not significantly different.