Prescribing antipsychotics in someone over 65 is not the same exercise as prescribing in someone over 25. Aging changes how drugs are absorbed, metabolised, and tolerated. The therapeutic window narrows. Side effects that were minor at 30 — orthostatic hypotension, sedation, constipation, parkinsonism — become major drivers of falls, hospitalisations, and death. Two documents shape the conversation: the AGS Beers Criteria and the FDA's boxed warning on antipsychotic use in elderly patients with dementia-related psychosis.
Antipsychotics in older adults must be started at lower doses, titrated slowly, monitored for falls and metabolic and cardiovascular effects, and used for the shortest time consistent with the indication.
How aging changes pharmacology
- Hepatic metabolism slows, raising plasma levels for most antipsychotics
- Renal clearance falls, particularly relevant for paliperidone
- Body fat composition rises, increasing the volume of distribution and prolonging half-lives
- Brain receptors are more sensitive to dopamine blockade, increasing risk of EPS, parkinsonism, and tardive dyskinesia
- Baroreceptor reflexes weaken, increasing orthostatic hypotension risk
- Anticholinergic burden from many medications worsens cognition and constipation
The general rule is to start at half the typical adult dose or lower and titrate more slowly than usual.
The Beers Criteria
The Beers Criteria, updated regularly by the American Geriatrics Society, lists medications that are potentially inappropriate in older adults. With antipsychotics, the relevant points are:
- First-generation and most second-generation antipsychotics are flagged as potentially inappropriate when used for behavioural problems of dementia or delirium unless non-pharmacological options have failed and the patient is a threat to self or others
- Schizophrenia, schizoaffective disorder, bipolar disorder, and adjunctive use in major depressive disorder are recognised as appropriate indications
- Anticholinergic-heavy antipsychotics (chlorpromazine, thioridazine, olanzapine at higher doses) deserve particular caution
The FDA boxed warning
In 2005 (atypicals) and 2008 (all antipsychotics), the FDA issued boxed warnings noting that elderly patients with dementia-related psychosis treated with antipsychotics are at increased risk of death, mostly from cardiovascular and infectious causes. This warning does not apply to schizophrenia treatment in older adults, but it shapes how clinicians approach every elderly patient with new psychotic symptoms.
Dosing principles
Specific doses must be individualised by a prescriber, but the broad principles for older adults are:
- Start low — often half or a quarter of typical adult starting doses
- Titrate slowly — sometimes weekly rather than every few days
- Aim for the lowest effective dose
- Reassess regularly whether the medication is still needed
- Use long-acting injectables thoughtfully — they reduce adherence problems but make rapid dose adjustments harder
What to monitor
- Vital signs — orthostatic blood pressure at every visit
- Weight and waist circumference — quarterly
- Fasting glucose, HbA1c, lipids — at baseline, 12 weeks, then yearly
- ECG — at baseline and periodically, especially for medications with QT prolongation risk
- Movement disorder screening — formal AIMS exam at least every 6 months
- Cognitive function — annual screening
- Fall history — at every visit; any fall should prompt a medication review
- Bone density — particularly if on prolactin-elevating medications long term
Choosing between medications
No single antipsychotic is "the" geriatric choice. Common considerations:
- Risperidone at low doses is widely used; paliperidone is similar but renally cleared
- Aripiprazole has a relatively favourable metabolic profile and the only FDA approval for dementia-related agitation in Alzheimer's
- Quetiapine at very low doses is sometimes chosen in Lewy body dementia for relative D2 sparing
- Olanzapine is effective but carries notable metabolic and anticholinergic burden
- Haloperidol and other first-generation antipsychotics carry higher EPS and tardive dyskinesia risk and are generally avoided long-term in older adults
- Clozapine remains the most effective option for treatment-resistant cases at any age, but monitoring becomes more complex and requires expertise
An older adult on an antipsychotic develops new falls, fainting, severe confusion, fever with rigidity, irregular heartbeat, or sudden inability to swallow — all warrant urgent evaluation.
What patients and families can ask
- What is the specific indication for this medication, and how long do we expect to use it?
- What is the lowest effective dose for this patient?
- How will we monitor for side effects, and how often?
- What is the plan for review and possible dose reduction?
- How does this medication interact with the rest of the medication list?
This article is for educational purposes only and is not medical advice, diagnosis, or treatment. Always consult a qualified mental health professional. If you or someone you know is in crisis, call or text 988 in the US, or your local emergency number.