Drug therapy in the elderly: special considerations.

The tendency toward polypharmacy in the elderly, combined with age-related physiologic changes, increases the risk for adverse effects resulting from the interference of one drug regimen with another. Altering drug dosages for concomitant drug regimens is important if the patient is to gain maximum benefit from the drugs with minimal adverse effects. Altered pharmacokinetics in the elderly, impaired drug response, and adverse effects of polypharmacy are each discussed with respect to drug absorption, distribution, metabolism, and elimination.