Pharmacological management of schizophrenia in older patients.

Although antipsychotic drugs are the mainstay of treatment in older patients with schizophrenia, much of the theoretical work underpinning their use is based on evidence gained from younger patients. With respect to dosages, there has been little work comparing plasma concentrations of antipsychotics in older patients with those of younger patients. However, there are well documented changes in the pharmacokinetics of these drugs in the elderly, particularly in their hepatic metabolism and renal excretion. There is also evidence that older patients experience more adverse effects from antipsychotics than younger patients. Such effects include extrapyramidal symptoms, postural hypotension and falls. For these reasons it is recommended that starting doses of antipsychotic drugs in older patients should be in the region of 25 to 50% of that recommended for younger patients, and should be slowly increased. Selection of a particular antipsychotic agent is best made on the basis of individual patient characteristics and the adverse effect profiles of particular drugs.