Abstract

THERAPEUTIC IMPLICATIONS OF METOPROLOL CHRONOTHERAPY IN HYPERTENSION

Mahvash Iram*, Shobha Rani R. H. and Nalini Pais

Abstract

Objective: Current project was aimed at monitoring the chronopharmacokinetics of metoprlol by measuring plasma concentrations with respect to time of administration and determine the optimal time for the administration. Method: After obtaining the informed consent from the patients, in-patients above 18 years of age and suffering from hypertension, ischemic heart disease and who were on metoprolol therapy were enrolled. Sampling of the plasma from these patients was carried out after steady state concentration was achieved. Peak and trough samples were collected and analysed using HPLC. Result: Total of 106 patients of whom, 58 formed the morning administration group and 48 evening administration group. All patients were above the age of 40 years, 61-70 (33.9%) years formed majority followed by 51-60 (27.3%) years ascertaining the fact that hypertension and its complications are age related. Patients who received morning dose of the drug showed higher plasma concentrations in comparison with evening dose. The mean plasma levels in the morning group were 11.3μg/ml (peak) and 5.2μg/ml (trough) and in the evening group were 8.4μg/ml (peak) and 2.8μg/ml (trough). The plasma concentrations of the drug clearly suggest that dosing of the drug at morning can help to control hypertension and early morning BP surge along with sympathetic activity. There was a clear significant different between the plasma concentrations of morning and evening group (P

Keywords: Chronotherapy, Evening, HPLC, Hypertension, Metoprolol, Morning, Plasma levels.