Start of therapy with the angiotensin II antagonist losartan after immediate switch from pretreatment with an ACE inhibitor.

AIMS

To evaluate initial blood pressure effects of the angiotensin II antagonist losartan (L) immediately after switching from an ACE inhibitor (captopril, C).

METHODS

Two-phase multicentre randomized study in 177 outpatients with mild to moderate essential hypertension. For 6 weeks all patients received 25 mg C twice daily. Then they were randomized double-blind to switch for another 6 weeks to 50 mg L once daily (n=110) or to maintain C (n=55). On the first day of the switch they underwent ambulatory blood pressure measurement (ABPM).

RESULTS

Within 12 h of first dose, 31% of patients who switched to L had two consecutive systolic BP readings of 30 mmHg below their individual baseline value compared with 24% of patients who stayed on C. In 3% of patients with L and in 6% of the C patients systolic BP readings less than 100 mmHg were recorded within 12 h of first dose. The differences were not statistically significant. There were no clinical symptoms attributable to initial hypotension. During the 6 weeks double-blind therapy, 9% of L patients experienced at least one adverse event, compared with 16% of patients with C.

CONCLUSIONS

In this study the angiotensin II antagonist losartan was effective and generally well tolerated when administered immediately after pretreatment with an ACE inhibitor.