Antihypertensive effect and safety of the newer, long acting, nonsulfhydryl angiotensin converting enzyme inhibitor, lisinopril, were studied.

Twenty eight patients of mild to moderate essential hypertension were administered 10-20mg of lisinopril once daily for ten weeks. Patients were evaluated every two weeks concerning the changes of blood pressure and pulse rate in the sitting position and also any untoward sumptoms and signs attributable to the side effect. Chest X-rey, ECG and laboratory examination were performed in principle two times before and after the completion of medication.

The blood pressure declined from 165.4/107.6mmHg to 141.3/92.4mmHg at the end of ten weeks of medication, thus the reduction of 24.1mmHg of systolic pressure and 15.2mmHg of diastolic pressure were observed and the overall effective rate was 85.7%. The pulse rate and laboratory findings were not sigificantly changed before and after the administration of lisinopril.

The side effects were observed in 2 cases(7.1%) of mild dry cough and in 2 cases(7.1%) of transitory mild headache and in 1 case(3.6%) of dizziness but no one discontinued medication due to adverse effects.

Lisinopril proved effective and safe in the treatment of mild to moderate essential hypertension.