Using pharmacokinetics in drug therapy. V: Contributions to developing dosage regimens for antihypertensive drugs.

Pharmacokinetic methods that have been used to improve antihypertensive drug therapy, including antihypertensive dosage regimens, are reviewed. Pharmacokinetic variables have been determined that allow: (1) derivation of the loading dose necessary to achieve rapid control of blood pressure with propranolol hydrochloride, guanethidine, minoxidil and clonidine hydrochloride; (2) reduced frequency of dosing with methyldopa, hydralazine hydrochloride, prazosin hydrochloride, propranolol and clonidine; and (3) alteration of propranolol and hydralazine dosage based on physiologic factors (e.g., renal and hepatic impairment, binding to plasma proteins, altered enzyme activity). More rapid control of hypertension is possible, patient compliance is enhanced and drug toxicity is reduced by applying pharmacokinetic principles to develop individualized antihypertensive dosage regimens.