Trough-to-peak ratio and circadian blood pressure profile after treatment with once-daily extended-release diltiazem, 240 mg, in patients with mild-to-moderate essential hypertension

Once-daily diltiazem extended-release 240 mg (Lacerol-HTA Retard) was evaluated for safety, efficacy, and trough-to-peak ratio in a multicenter open study by using 24-h blood pressure (BP) monitoring in mild-to-moderate essential hypertension. After a 4-week washout period, 30 patients (17 men, 13 women) aged 25-76 years, showing a mean daytime diastolic BP (DBP) >90 mm Hg, were treated with diltiazem-ER, 240 mg, given once daily for 8 weeks. Ambulatory BP monitoring was obtained at the end of a 4-week placebo run-in period and during the last week of treatment. A significant reduction of the mean values of clinical BP [161.6 +/- 16.2 to 151.2 +/- 15.6 mm Hg; p < 0.01 for systolic BP (SBP); and 101.1 +/- 4.8 to 93.3 +/- 9.2 mm Hg; p < 0.001 for DBP] was observed at the end of treatment in the group of 30 patients, with no significant changes in heart rate (77.1 +/- 9.9 to 73.1 +/- 11.1 beats/min; p = NS). Likewise, mean values of 24-h SBP, DBP, SBP-load, and DBP-load were significantly reduced. In the group of 21 responders, the average reduction at peak was -18.6 +/- 12.9 mm Hg for SBP and 14.7 +/- 9.5 mm Hg for DBP. The residual effect at trough was -12.2 +/- 14.7 and -8.1 +/- 10 mm Hg, respectively. The trough-to-peak ratio was estimated as 0.66 for SBP and 0.55 for DBP. Long-term variability expressed as the mean standard deviation of BP for the 24-h period was reduced in responders (16.2 +/- 4.3 to 14.6 +/- 2.7 mm Hg for SBP; p = 0.0395; and 12.1 +/- 2.7 to 10.7 +/- 2.5 mm Hg for DBP; p = 0.0019), although no changes were observed in the variation coefficient (10.58-10.57% for SBP and 12.88-12.87% for DBP). We conclude that once-daily diltiazem-ER, 240 mg, was effective and well tolerated. Blood pressure was controlled over the entire period of 24 h, preserving the circadian profile and reducing long-term variability in responders. The significant reduction of both BP values and long-term variability may have implications involving protection from endorgan damage in essential hypertension.