Canadian journal of psychiatry. Revue canadienne de psychiatrie
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Review
Psychotropic medications and cytochrome P450 2D6: pharmacokinetic considerations in the elderly.
The genetically polymorphic cytochrome P450 2D6 isozyme (CYP2D6) is responsible for the metabolism of numerous psychotropic medications pertinent to the practice of geriatric psychiatry. Optimal use of psychotropics in the elderly requires a thorough understanding of the determinants of marked variability in plasma concentrations. This review article will focus on basic pharmacokinetic considerations for elderly patients when psychotropics metabolized by CYP2D6, such as nortriptyline and desipramine, are prescribed. ⋯ Clinical measurement of CYP2D6 activity may potentially assist in prediction of doses required to achieve therapeutic plasma concentrations of psychotropics metabolized by CYP2D6 in individual patients. Although CYP2D6 activity does not change with age, the pharmacokinetics of psychotropics metabolized by CYP2D6 may change because of age-associated changes in hepatic blood flow, volume of distribution, and renal elimination of metabolites.