title: Comparison of the effects of amlodipine and losartan on 24-hour ambulatory blood pressure in hypertensive patients.
abstract: Effects of amlodipine (AML), a long-acting calcium antagonist, and losartan (LOS), an angiotensin II receptor antagonist, on 24-hr blood pressure profile were compared in 15 patients with essential hypertension. After 4 weeks of placebo period, the patients were treated with AML or LOS in a random crossover design for 12-16 weeks each. Either drug was given once daily at 0800 and the doses were titrated so that the office blood pressure was reduced lower than 140/90mmHg. At the end of each period, 24-hr blood pressure was monitored. Average office blood pressure was lowered from 158 +/- 2/ 98 +/- 2 mmHg to 134 +/- 1/87 +/- 1 mmHg by AML and 134 +/- 2/88 +/- 1 mmHg by LOS. Average 24-hr blood pressure was also reduced from 144 +/- 3/ 92 +/- 2 mmHg to 131 +/- 2/84 +/- 2 mmHg by AML and 135 +/- 3/85 +/- 2 mmHg by LOS. The averaged 24-hr systolic blood pressure was significantly lower in AML than in LOS (p < 0.05). Then, the 24-hr blood pressure was analyzed for four segments; morning (0530-0900 h), daytime (0930-1800 h), evening (1830-2300 h) and night (2330-0500 h). Although the daytime blood pressure was comparable between AML and LOS, systolic blood pressure in the evening and morning hours were lower in AML than in LOS (133 +/- 2 vs. 138 +/- 3mmHg,p<0.01; 129 +/- 3 vs. 134 +/- 4,p<0.05). Troughtopeakratio of antihypertensive effect on systolic blood pressure was significantly greater in AML than in LOS (62 +/- 5% vs. 55 +/- 4%, p < 0.05). Either drug did not cause reflective increase in pulse rate over 24 hours. These results suggest that both AML and LOS are equally effective in lowering daytime blood pressure without eliciting reflex tachycardia, however, the antihypertensive effect of AML lasts longer than that of LOS. Such information seems important to achieve 24-hr blood pressure control using these drugs.
authors.affiliation: Department of Hypertension and Cardiorenal Medicine, Dokkyo University School of Medicine, Mibu, Tochigi, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Ishimitsu
authors.forename: J
authors.initials: J
authors.lastname: Minami
authors.forename: M
authors.initials: M
authors.lastname: Yoshii
authors.forename: T
authors.initials: T
authors.lastname: Suzuki
authors.forename: H
authors.initials: H
authors.lastname: Inada
authors.forename: S
authors.initials: S
authors.lastname: Ohta
authors.forename: Y
authors.initials: Y
authors.lastname: Futoh
authors.forename: H
authors.initials: H
authors.lastname: Ono
authors.forename: H
authors.initials: H
authors.lastname: Matsuoka
mesh_terms: D000328:Adult; D000368:Aged; D017311:Amlodipine / Q000627:therapeutic use*; D057911:Angiotensin Receptor Antagonists; D000959:Antihypertensive Agents / Q000627:therapeutic use*; D001794:Blood Pressure / Q000187:drug effects*; D018660:Blood Pressure Monitoring, Ambulatory; D002121:Calcium Channel Blockers / Q000627:therapeutic use*; D002940:Circadian Rhythm; D018592:Cross-Over Studies; D006801:Humans; D006973:Hypertension / Q000188:drug therapy* / Q000503:physiopathology*; D019808:Losartan / Q000627:therapeutic use*; D008875:Middle Aged
chemical_list: D057911:Angiotensin Receptor Antagonists; D000959:Antihypertensive Agents; D002121:Calcium Channel Blockers; D017311:Amlodipine; D019808:Losartan