Alpha 1-adrenoceptor responsiveness: the influence of age.

The association between increasing age and increasing blood pressure is the principal factor that has compromised the interpretation of many studies attempting to evaluate the effects of age alone on alpha-adrenergic mechanisms and the antihypertensive response to alpha 1-adrenoceptor antagonists. In clinical studies of antihypertensive response, difficulties of interpretation have been created by the failure to take into account the statistical association between the initial blood pressure and magnitude of the blood pressure fall and also the potential influence of age-related alterations in pharmacokinetics and drug disposition. Only a few studies have integrated pharmacokinetic and pharmacodynamic information to quantify more accurately responsiveness to alpha-antagonist drugs. These studies have failed to show any independent age-related differential effect but have confirmed that the pretreatment blood pressure, irrespective of age, is a significant determinant of the antihypertensive response.