Canadian valsartan study in patients with mild-to-moderate hypertension

This study was designed mainly to establish the rates of response to valsartan 80mg once daily (qd) and to valsartan 160mg qd given to non-responders to 80mg qd, as well as to determine the safety of valsartan and the blood pressure control achieved using valsartan over a period of 24 h or more, using ambulatory blood pressure monitoring (ABPM) devices.

This was a single-blind, single-arm, multicenter study involving 256 out-patients with mild-to-moderate essential hypertension. After previous antihypertensive treatments had been 'washed out', the patients were entered into a 2-week placebo run-in period to confirm the diagnosis of mild-to-moderate hypertension. Patients who, at the end of the placebo run-in period, had a mean sitting diastolic blood pressure of between 95 and 115mmHg inclusive received valsartan 80mg qd for 4 weeks. Non-responders (those not demonstrating a diastolic blood pressure of less than 90mmHg or a decrease in diastolic blood pressure of 10mmHg or more compared with baseline) received valsartan 160mg qd for another 4 weeks. In selected centers, patients who agreed also had their blood pressure monitored for 24 h, provided their blood pressure was shown to be controlled. Of these patients, half skipped one dose of valsartan and were monitored for an additional 24h period.

The rate of response to valsartan 80mg was 45.4%, and of those not responding to this dose, 36.3% responded to valsartan 160mg. The response rate to one or other dose was 63.2%. The ambulatory blood pressure data support a consistent reduction of blood pressure with valsartan over a 24h period and for up to 32 h after dosing in those who missed a dose. The overall incidence of adverse experiences per person-year, treatment related or otherwise, was 6.3 and 10.6 for the valsartan and placebo study periods respectively.

Antihypertensive treatment with valsartan for 8 weeks produced a significant decrease in diastolic blood pressure in hypertensive patients. In addition, the drug may be safely administered, and the results of 24 h/48 h ambulatory monitoring demonstrate that valsartan is a true once-a-day antihypertensive.