Abstract
Coughing is an adverse reaction to angiotensin-converting enzyme (ACE) inhibitors, but some ACE inhibitors cause more coughing than others. To test the hypothesis that this difference is related to a difference in their effects on bradykinin (BK), the potencies for inhibition of the hydrolysis of BK and angiotensin (Ang) I of four ACE inhibitors, captopril, enalaprilat, ramiprilat, and imidaprilat, were tested with purified canine lung ACE. The accumulation of BK relative to the inhibition of Ang II formation was significantly less with imidaprilat than with the three other ACE inhibitors. This may explain why imidapril was associated with less coughing than ramipril in clinical trials. ACE inhibitors may be classified by their relative potencies for the inhibition of the hydrolysis of BK and Ang I. (Hypertens Res 1994; 17: 253-258)
