Altered pharmacokinetics in the elderly.

Physiologic changes that occur in the aging process may directly affect drug pharmacokinetics. Alteration of the pharmacokinetics of these drugs in the elderly may necessitate adjustment of drug dosages to prevent toxicity or inadequate therapy. Whereas clinical tests to measure renal function may be used quantitatively to prospectively individualize a drug dosage to an elderly patient, tests for hepatic function do not correlate as well with changes in hepatic drug metabolism. Despite these limitations, recognition of the relationship between physiologic changes and drug pharmacokinetics is important to better prescribe the correct dose in the elderly population.