Background: Early morning blood pressure (BP) surge and 24 h mean BP are linked to target-organ damage and cardiovascular events. Antihypertensive agents should sustain BP control, particularly in the last 6 h of the dosing interval or if dosing is missed. The efficacies of the long half-life telmisartan compared with shorter half-life valsartan in the last 6 h of the dosing interval following active treatment and during 24 h after a missed dose were compared.
Methods: In two identically designed multinational, randomized, double-blind, forced-titration studies, hypertensive patients (seated diastolic blood pressure (DBP), 95-109 mm Hg, 24 h mean ambulatory DBP, > or = 85 mm Hg) received once-daily telmisartan (40- 80 mg) or valsartan (80-160 mg) for a total of 8 weeks; uptitration occurred after 2 weeks low-dose treatment. After 4 weeks high-dose treatment, patients were given either 1 days double-blind active therapy or placebo (that is, missed dose). Following a further 2 weeks active treatment, a cross-over was performed: patients who had previously received 1 days placebo received active therapy and vice versa. At baseline and after the two active or missed doses, 24 h ambulatory BP monitoring was performed. Data from the studies were pooled, as prospectively planned and analyzed using the intent-to-treat population.
Results: After active therapy, last 6 h mean DBP was reduced by 7.6+/-7.9 mm Hg with telmisartan (n=447) compared with 5.8+/-7.8 mm Hg with valsartan (n=430) (P=0.0044). Last 6 h mean systolic blood pressure (SBP) was reduced by 11.1 mm Hg with telmisartan compared with 9.1 mm Hg with valsartan (P=0.0066). After a missed dose, 24 h mean DBP was reduced by 7.2+/-6.5 mm Hg with telmisartan (n=437) compared with 5.5+/-6.2 mm Hg with valsartan (n=431) (P=0.0004). The reduction in 24 h mean SBP after a missed dose was 10.7 mm Hg with telmisartan and 8.7 mm Hg with valsartan (P=0.0024). Absence of treatment-by-study interaction indicated that pooling of studies was appropriate. All 24 hourly mean reductions in DBP and SBP were greater for telmisartan than valsartan. Both treatments were well tolerated.
Conclusions: Due to its longer half-life, telmisartan offers more sustained BP control, especially at the end of the dosing period and provides sustained efficacy in poorly compliant patients in the event of a missed dose with a statistical superiority compared with valsartan.