There are many considerations for clinicians who treat older adults with schizophrenia. Summarized here are the recommendations for the specialized population of older adults from APA’s Practice Guideline for the Treatment of Patients with Schizophrenia (released in 2020, finalized in 2021).
Pharmacokinetic properties for older adults (age greater than 55) are essential to understand and guide prescribing. These include: reduced renal and hepatic blood flow, reduced glomerular filtration rate (GFR), potentially reduced hepatic metabolism, increased ratio of fat to muscle mass. Short-term, intramuscular antipsychotic medication elimination half-life will be estimated 1.5 times greater for older adults.
Older adults are more sensitive to side effects of antipsychotic medications. These include: tardive dyskinesia (TD), orthostatic hypotension, and anticholinergic effects such as constipation, urinary retention, and impaired cognition. Certain antipsychotic medications increase the propensity to cause anticholinergic effects, in particular clozapine and olanzapine.
Initiation of antipsychotic medications for older adults have recommended starting doses of ¼ to ½ the usual adult starting doses. If prescribing clozapine for older adults, clinicians should utilize a slower titration to avoid side effects. Clozapine levels on specific dosages will reflect as higher for older adults compared to younger patients. With clozapine, older adults and patients with peripheral vascular disease are at increased risk of orthostatic hypotension.
When managing common side effects of antipsychotic medications, special considerations are recommended for treating older adults for acute dystonia, parkinsonism, and akathisia. Anticholinergic medications are indicated to treat acute dystonia, but older adults are more sensitive to anticholinergic effects. These include: urinary retention, confusion, constipation and fecal impaction, blurred vision, tachycardia, thermoregulation instability, and anticholinergic toxicity (delirium, somnolence, and hallucinations). If Parkinsonism treatment is required, increasing the dosing interval or reducing the dose is recommended for older adults or for patients with renal impairment. Finally, if benzodiazepines are utilized to treat akathisia, clinicians should consider that these agents decrease coordination and increase the likelihood of falls for older adults.
The full practice guideline can be found here: American Psychiatric Association. (2021). The American Psychiatric Association Practice Guideline for the Treatment of Patients With Schizophrenia. American Psychiatric Association Publishing (3rd ed.).
An informative webinar covering highlights of the practice guideline can be found here: The American Psychiatric Association Guideline for Treatment of Patients with Schizophrenia