A Tipping Point in Drug Dosing in Late-Life Schizophrenia

Abstract

Minimally effective doses of antipsychotics are likely influenced by several clinical and demographic characteristics of patients, with age being one of the most important elements. In light of age-related physiologic changes as well as interindividual differences in pharmacokinetic and pharmacodynamic systems, individualized dosing with regard to age will be critically important for safer drug treatment for older patients with schizophrenia. In the present review, we propose the following cautious psychopharmacologic interventions for this population: 1) simple regimen (avoid polypharmacy), 2) be aware of the presence of patients who are very sensitive to drugs, 3) gradual dose titration, and 4) timely and thorough assessments of therapeutic and side effects. The age-related antipsychotic sensitivity highlights the importance of finding the lowest possible effective dose of antipsychotic drugs as patients with schizophrenia age to maximize therapeutic effects and minimize side effects.

Psychosis in Later Life

“…Of special note here is that older patients are likely more sensitive than younger patients to the side effects of antipsychotics-in particular, the motor side effects. 91 The type of adverse effect depends on the particular antipsychotic used, but common examples include sedation, anticholinergic effects, cardiovascular effects, extrapyramidal symptoms and tardive dyskinesia, metabolic effects, hyperprolactinemia, and, less commonly, agranulocytosis (most commonly with clozapine use) and neuroleptic malignant syndrome. 92 Although many of these side effects are associated with both typical and atypical antipsychotics, motor symptoms are more commonly associated with the former and metabolic symptoms with the latter.…”

Prevention of antipsychotic side effects in elderly populations

“…The core treatment for schizophrenia is antipsychotic medication, although the choice of an optimal drug regimen varies with patient preference, co-morbidities, adverse drug effects, and interactions with co-administered drugs. In general, guidebook antipsychotic doses for schizophrenia are too high for the elderly; most investigators recommend a gradual reduction of dosages in older age [1]. This is because liver and kidney function deteriorates with age and body composition changes, affecting drug distribution, metabolism, and elimination.…”