Effects of dividing amlodipine daily doses on trough drug concentrations and blood pressure control over a 24-hour period.

Abstract

BACKGROUND:

In the treatment of hypertension, once-daily administration of long-acting antihypertensive drugs has been recommended for the improvement of treatment adherence; however, it is unclear whether dividing daily doses has the additional benefit of more ideal blood pressure (BP) control over a 24-hour period.

OBJECTIVE:

The aim of the study was to investigate whether dividing a 10-mg daily dose of amlodipine, a long-acting calcium channel blocker, is associated with increased trough plasma amlodipine concentrations, reduced arterial stiffness, and improved BP control over a 24-hour period.

METHODS:

Outpatients with essential hypertension were included this open-label, 2-period crossover study. The patients were administered amlodipine 10 mg/d in 2 divided doses for 8 weeks. At week 4, blood was collected just before amlodipine administration for the evaluation of trough plasma amlodipine concentrations. At week 8, 24-hour, daytime, nighttime, and early morning BP, as well as arterial stiffness, were measured using ambulatory BP monitoring (ABPM) and cardio-ankle vascular index (CAVI), respectively. In the subsequent study period, amlodipine 10 mg/d was administered once daily, and the same tests were performed at the same timings as in period 1.

RESULTS:

Ten patients were enrolled (7 men, 3 women; mean age, 61.0 [15.3] years). Mean 24-hour BP with twice-daily administration was not significantly lower than that with once-daily administration (129.7 [7.3]/80.1 [7.9] mm Hg vs 130.5 [11.8]/80.1 [7.9] mm Hg, respectively). Similarly, there were no significant differences in daytime, nighttime, or early morning BP between twice- and once-daily administration. In addition, the differences in trough plasma amlodipine concentrations (22.37 [7.66] ng/mL vs 20.57 [8.22] ng/mL) and CAVI values (8.2 [1.8] vs 8.5 [1.0]) were not significantly different between twice- and once-daily administration.

CONCLUSIONS:

Administering amlodipine in 2 divided doses was not associated with increased trough plasma amlodipine concentrations, reduced arterial stiffness, or improved BP control over a 24-hour period in patients with essential hypertension.

• Authors: Ken-ichi Miyoshi, Takafumi Okura, Tomoaki Nagao, Jotoku Masanori, Jun Irita, Jitsuo Higaki
• Journal: Clinical therapeutics (Clin Ther) Vol. 35 Issue 9 Pg. 1418-22 (Sep 2013) ISSN: 1879-114X [Electronic] United States
• PMID: 23972579 (Publication Type: Clinical Trial, Journal Article)
• Copyright: © 2013 Elsevier HS Journals, Inc. All rights reserved.

Chemical References

• Antihypertensive Agents
• Amlodipine

Topics

• Aged
• Amlodipine (administration & dosage, blood, therapeutic use)
• Antihypertensive Agents (administration & dosage, blood, therapeutic use)
• Blood Pressure (drug effects)
• Blood Pressure Monitoring, Ambulatory
• Cross-Over Studies
• Drug Administration Schedule
• Essential Hypertension
• Female
• Humans
• Hypertension (drug therapy)
• Male
• Middle Aged
• Patient Compliance
• Vascular Stiffness (drug effects)