LOW-DOSE VERAPAMIL IN MIDDLE-AGED AND ELDERLY PATIENTS WITH ANGINA-PECTORIS - NO EVIDENCE OF INCREASED SUSCEPTIBILITY TO THE CARDIAC EFFECTS

This study investigated the cardiac responses and pharmacokinetics following the acute and chronic administration of verapamil in 14 middle-aged and elderly patients with ischemic heart disease (age range 42-76 years). There were small significant reductions in heart rate during chronic treatment, but there were no significant effects on the PR intervals following either single intravenous administration or after 4 weeks continued treatment. Left ventricular ejection fractions at rest or exercise were not significantly changed following either acute intravenous (rest 33%; exercise 38%) or chronic oral dosing with verapamil (rest 35%; exercise 43%) when compared with placebo (rest 34%; exercise 42%). There were no independent age-related effects on these indices of cardiac function, nor on apparent liver blood flow, nor on blood pressure and heart rate. The plasma clearance of verapamil was reduced from 1.3 l/min after acute dosing to 0.8 l/min during chronic treatment, but there was no significant independent age-related effect. The results of this study suggest that middle-aged and elderly patients with ischemic heart disease do not show enhanced cardiovascular responses to low doses (5 mg intravenously and 80 mg tid orally) of the calcium antagonist drug, verapamil.