Effect of enalapril on the skin response to bradykinin in man

We tested the effect of oral enalapril on intradermal bradykinin to determine if kininase II inhibition occurs with therapeutic doses in vivo. Six normal male volunteers took either 5 mg enalapril orally or placebo on 2 days. Three hours later bradykinin was injected into the skin of the back in doses increasing from 10(-11) to 10(-9) M. Enalapril increased the bradykinin-induced wheal. Inhibition of kininase II may cause accumulation of endogenous bradykinin. This could be an important mechanism in the occasionally reported side effect of angioedema with the angiotensin converting enzyme (ACE) inhibiting group of drugs.