In conclusion, our study did not show any difference
in blood pressure lowering efficacy between enalapril20
mg 0.d. and lisinopril20 mg 0.d. in patients with mild to
moderate hypertension, not even 18-24 h post-dose
even though the blood pressure changes were evaluated
in a more comprehensive way than in earlier studies of
these drugs. Furthermore, lisinopril but not enalapril
halved ACE activity in serum after 4 weeks of active
treatment, supporting the claim that there are other
mechanisms than ACE activity in serum that are
responsible for the blood pressure lowering effect of
ACE inhibitors, at least in chronic treatment.