Factors influencing the responses to calcium antagonists in elderly patients with hypertension and ischaemic heart disease.

The results of a variety of studies that have investigated the effect of age on the pharmacokinetics and pharmacodynamics of calcium antagonist drugs have produced the following conclusions. Primarily, as a result of an age-dependent decline in plasma drug clearance, there is a tendency for elderly patients to have higher plasma drug concentrations than young patients. In terms of pharmacological response, there is good evidence of therapeutic efficacy in both hypertension and ischaemic heart disease, but there is no convincing evidence of any preferential age-related effect, particularly in relation to blood pressure reduction. Similarly and conversely, there is no convincing evidence that the elderly are at greater risk from the adverse effects of calcium antagonist drugs, particularly those which reflect the negative effects on cardiac conduction. An integrated mathematical method for describing antihypertensive response, which incorporates both pharmacokinetic and pharmacodynamic information, has been used to investigate the variability in antihypertensive effect with nifedipine and verapamil. There was no relationship between responsiveness (in mmHg/ng/mL) and patient age and plasma renin activity; however, responsiveness during chronic treatment was directly correlated with the height of the starting blood pressure and the response to the first dose.