The pharmacokinetics of amlodipine besylate are not significantly influenced by renal impairment. Patients with renal failure may therefore receive the usual initial dose. These decreases in blood pressure are not accompanied by a significant change in heart rate or plasma catecholamine levels with chronic dosing. Although the acute intravenous administration of amlodipine decreases arterial blood pressure and increases heart rate in hemodynamic studies of patients with chronic stable angina, chronic administration of oral amlodipine in clinical trials did not lead to clinically significant changes in heart rate or blood pressures in normotensive patients with angina. With chronic once daily oral administration, antihypertensive effectiveness is maintained for at least 24 hours.
Plasma concentrations correlate with effect in both young and elderly patients.
Similar findings, however, have been observed in normals or well-compensated patients with heart failure with agents possessing significant negative inotropic effects. Studies in patients with NYHA Class IV heart failure have not been performed and, in general, all calcium channel blockers should be used with caution in any patient with heart failure. In hypertensive patients with normal renal function, therapeutic doses of amlodipine besylate resulted in a decrease in renal vascular resistance and an increase in glomerular filtration rate and effective renal plasma flow without change in filtration fraction or proteinuria. Electrophysiologic Effects Amlodipine besylate does not change sinoatrial nodal function or atrioventricular conduction in intact animals or man. Similar results were obtained in patients receiving amlodipine besylate and concomitant beta blockers.