[Pharmacokinetics in the elderly]

Physiological changes that occur in the aging process may directly affect drug pharmacokinetics. In the absence of disease or other pathologic conditions, age-related changes in pharmacokinetics principally affect drug absorption, distribution, metabolism or elimination. One factor that does change consistently with age is renal clearance, consequently a common pharmacokinetic change is reduced drug clearance, especially for drugs excreted largely unchanged by the kidneys. Alteration of the pharmacokinetics of drugs in the elderly may necessitate adjustment of dosages to prevent toxicity or inadequate therapy. As a broad generalization, dosage should be reduced in elderly patients, reflecting the general decline in body function with age.