A comparison of the efficacy and duration of action of telmisartan, amlodipine and ramipril in patients with confirmed ambulatory hypertension.
OBJECTIVE
The aim of the study was to compare the antihypertensive effects and the duration of action of telmisartan, amlodipine and ramipril in patients with mild-to-moderate hypertension using ambulatory blood pressure (ABP) monitoring.


METHODS
After a 2-4-week single-blind, placebo run-in period, qualifying patients were randomized to receive telmisartan 80 mg (n=18); amlodipine 5 mg (n=22); titrated to 10 mg after 4 weeks; or ramipril 2.5 mg (n=17); titrated to 5 mg and 10 mg after 1 and 3 weeks, respectively, administered once daily in the morning (0700 h). Ambulatory blood pressure monitoring was performed at baseline and at the end of the 8-week treatment period. Plasma renin activity was measured over 24 h at the same time points.


RESULTS
Telmisartan and amlodipine provided significant reductions from baseline (P<0.0001) and not statistically different reductions between treatments in ABP during daytime (9.3/6.0 and 14.7/9.4 mmHg, respectively) and night-time (12.4/7.7 and 13.3/8.6 mmHg, respectively) at the end of 8 weeks' treatment. In contrast, although ramipril provided significant reductions in ambulatory systolic and diastolic BP from 2-6 h post dose (peak effect), it failed to induce significant reductions in mean daytime (4.5/1.6 mmHg) and night-time (1.8/0.1 mmHg) ambulatory BP. In addition, the greater reductions in ABP with telmisartan and amlodipine were associated with a significant rise in plasma renin activity whereas ramipril only increased renin during the first 4 h of the administration interval.


CONCLUSIONS
The results of the present study confirm the efficacy of both telmisartan and amlodipine in reducing ABP during each period of the 24-h interval. Because ABP reduction with ramipril was restricted to its peak effect, the present data do not support the use of this agent when administered once daily in the morning.
Unité d'hypertension, Centre Hospitalier de l'Université Laval, Université Laval, 2705 Boulevard Laurier S-120-A, Sainte-Foy, Quebec, Canada G1V 4G2. luc.poirier@crchul.ulaval.ca
Luc
L
Poirier
Jacques
J
de Champlain
Pierre
P
Larochelle
Maxime
M
Lamarre-Cliche
Yves
Y
Lacourcière
D000368:Aged; D017311:Amlodipine / Q000008:administration & dosage / Q000493:pharmacokinetics; D047228:Angiotensin II Type 1 Receptor Blockers / Q000008:administration & dosage / Q000493:pharmacokinetics; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000008:administration & dosage / Q000493:pharmacokinetics*; D001562:Benzimidazoles / Q000008:administration & dosage / Q000493:pharmacokinetics; D001565:Benzoates / Q000008:administration & dosage / Q000493:pharmacokinetics; D001794:Blood Pressure / Q000187:drug effects; D018660:Blood Pressure Monitoring, Ambulatory; D002940:Circadian Rhythm; D005260:Female; D006801:Humans; D006973:Hypertension / Q000188:drug therapy*; D008297:Male; D008875:Middle Aged; D017257:Ramipril / Q000008:administration & dosage / Q000493:pharmacokinetics; D012083:Renin / Q000097:blood; D000077333:Telmisartan; D013810:Therapeutic Equivalency
D047228:Angiotensin II Type 1 Receptor Blockers; D000806:Angiotensin-Converting Enzyme Inhibitors; D001562:Benzimidazoles; D001565:Benzoates; D017311:Amlodipine; D012083:Renin; D017257:Ramipril; D000077333:Telmisartan