What are the best practices for prescribing psychiatric medications to a patient over 65, including first‑line drug choices, dosing, and safety monitoring for depression, anxiety, psychosis, dementia‑related behavioral disturbances, and insomnia?

Prescribing Psychiatric Medications in Geriatric Patients (≥65 Years)

Depression

First-Line Pharmacotherapy

Sertraline (25–50 mg daily, maximum 200 mg) or escitalopram (10 mg daily, maximum 20 mg in patients >60 years) are the preferred first-line antidepressants for older adults due to minimal drug interactions, excellent tolerability, and favorable safety profiles. 1

• Start at 50% of the standard adult dose and titrate slowly, increasing every 1–2 weeks for shorter half-life agents (sertraline) or 3–4 weeks for longer half-life agents (escitalopram). 1
• Allow 4–8 weeks at optimized dose for full therapeutic assessment before declaring treatment failure. 1
• Avoid paroxetine (significant anticholinergic properties, increased suicidal thinking risk) and fluoxetine (very long half-life, extensive CYP2D6 interactions, higher agitation rates). 1

Monitoring and Duration

• Assess response at 4 weeks and 8 weeks using standardized instruments (e.g., PHQ-9). 1
• Monitor for hyponatremia (0.5–12% incidence, typically within first month), QT prolongation with citalopram/escitalopram (obtain ECG if dose >20 mg in patients >60 years), and GI bleeding risk (especially with concurrent NSAIDs/anticoagulants—add PPI prophylaxis). 1
• Continue treatment for 9 months after first episode, then reassess; longer-term treatment for recurrent depression. 1
• Taper gradually over 10–14 days when discontinuing to avoid withdrawal syndrome (dizziness, paresthesias, anxiety, irritability). 1

Treatment-Resistant Depression

• After two adequate SSRI trials (8 weeks each at therapeutic dose), switch to an SNRI (venlafaxine or duloxetine) rather than cycling through additional SSRIs. 1
• Screen for obstructive sleep apnea (present in 25–50% of treatment-resistant depression)—initiate CPAP before further medication adjustments if confirmed. 2
• Consider augmentation with low-dose aripiprazole (2–5 mg daily) only after multiple failed trials, recognizing increased mortality risk in elderly dementia patients. 3

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Anxiety Disorders

First-Line Treatment

Cognitive behavioral therapy (CBT) is the psychotherapy with the highest level of evidence for anxiety disorders in all age groups and should be offered first unless severity demands immediate pharmacological intervention. 1

• If pharmacotherapy is required, sertraline (25 mg daily) or escitalopram (10 mg daily) are first-line, using the same dosing principles as for depression. 1
• Buspirone (5 mg twice daily, titrate to maximum 20 mg three times daily) is a suitable alternative for mild-to-moderate anxiety in relatively healthy elderly patients, but requires 2–4 weeks to become effective. 1

Medications to Avoid

Benzodiazepines should be strongly avoided in older adults due to increased risk of cognitive impairment, delirium, falls, fractures (OR 1.42), dependence, and paradoxical agitation in approximately 10% of elderly patients. 1, 4

• If a benzodiazepine is absolutely necessary for acute management only, use lorazepam 0.25–0.5 mg (maximum 2 mg in 24 hours), then taper over 10–14 days. 1, 4
• Never combine benzodiazepines with opioids (respiratory depression risk) or use routinely in patients with cognitive impairment. 1

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Psychosis (Schizophrenia, Delusional Disorder, Psychotic Mood Disorders)

Late-Life Schizophrenia

Risperidone (1.25–3.5 mg daily) is the first-line antipsychotic for late-life schizophrenia, with quetiapine (100–300 mg daily), olanzapine (7.5–15 mg daily), and aripiprazole (15–30 mg daily) as high second-line options. 5

• Start at 25% of the usual adult dose in elderly patients; maintenance doses range from 25–50% of adult doses. 6
• Avoid typical antipsychotics (haloperidol, fluphenazine) as first-line due to 50% risk of tardive dyskinesia after 2 years of continuous use in elderly patients. 3

Psychotic Major Depression

An antipsychotic plus an antidepressant (98% expert consensus) is first-line treatment, with ECT as an alternative first-line option (71% expert consensus). 5

• Preferred combinations: risperidone 0.5–2 mg + SSRI or quetiapine 50–150 mg + SSRI. 5
• Continue antipsychotic for 6 months after remission, then attempt taper. 5

Delusional Disorder

An antipsychotic alone is the only recommended treatment for delusional disorder in older adults. 5

• Continue for 6 months to indefinitely at the lowest effective dose. 5

Safety Monitoring for All Antipsychotics

• Discuss increased mortality risk (1.6–1.7 times higher than placebo in elderly dementia patients) with patient/surrogate before initiating. 3
• Monitor for extrapyramidal symptoms, falls, metabolic changes (weight, glucose, lipids), QT prolongation, orthostatic hypotension, and cognitive worsening. 3
• Daily in-person examination when initiating or adjusting doses. 3

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Dementia-Related Behavioral Disturbances

Non-Pharmacological Interventions (Mandatory First-Line)

Behavioral and environmental interventions must be attempted and documented as failed before any medication is prescribed for agitation in dementia. 3

• Systematically investigate and treat reversible causes: pain (major contributor), urinary tract infections, pneumonia, constipation, urinary retention, dehydration, hypoxia, electrolyte abnormalities, medication side effects (especially anticholinergics). 3
• Environmental modifications: adequate lighting (especially late afternoon for sundowning), reduced noise, predictable daily routines, calm tones, simple one-step commands, gentle touch, morning bright light exposure (2 hours at 3,000–5,000 lux). 3
• Caregiver education: behaviors are symptoms of dementia, not intentional actions; teach "three R's" (repeat, reassure, redirect). 3

Pharmacological Treatment Algorithm

Step 1: Chronic Agitation Without Psychotic Features

SSRIs (citalopram 10 mg daily, maximum 40 mg; or sertraline 25–50 mg daily, maximum 200 mg) are first-line pharmacological treatment for chronic agitation in dementia. 3

• SSRIs significantly reduce overall neuropsychiatric symptoms, agitation, and depression in vascular cognitive impairment and dementia. 3
• Assess response at 4 weeks; if no clinically significant improvement after 4 weeks at adequate dose, taper and withdraw. 3
• Trazodone (25 mg daily, maximum 200–400 mg in divided doses) is a second-line option if SSRIs fail or are not tolerated, but use caution in patients with premature ventricular contractions (orthostatic hypotension risk). 3

Step 2: Severe Agitation With Psychotic Features or Aggression

Medications should only be used when the patient is severely agitated, threatening substantial harm to self or others, and behavioral interventions have failed. 3

• Risperidone (0.25 mg at bedtime, target 0.5–1.25 mg daily) is first-line for severe agitation with psychosis. 3
• Quetiapine (12.5 mg twice daily, maximum 200 mg twice daily) is an alternative, but more sedating with orthostatic hypotension risk. 3
• Olanzapine (2.5 mg at bedtime, maximum 10 mg daily) is generally well-tolerated but less effective in patients over 75 years. 3, 5

Step 3: Acute Severe Agitation (Emergency Situations)

Haloperidol (0.5–1 mg orally or subcutaneously, maximum 5 mg daily) is preferred for acute severe agitation with imminent risk of harm when behavioral interventions have failed. 3

• Higher initial doses (>1 mg) provide no additional benefit and significantly increase adverse effects. 3
• Benzodiazepines should not be first-line for agitated delirium (except alcohol/benzodiazepine withdrawal) because they increase delirium incidence and duration, cause paradoxical agitation in ~10% of elderly patients, and risk respiratory depression. 3

Duration and Tapering

• Use antipsychotics at the lowest effective dose for the shortest possible duration. 3
• Attempt taper within 3–6 months to determine lowest effective maintenance dose; approximately 47% of patients continue receiving antipsychotics after discharge without clear indication. 3
• Review need at every visit and discontinue if no longer indicated. 3

Special Populations

Vascular Dementia

SSRIs (citalopram or sertraline) are explicitly designated as first-line pharmacological treatment for agitation in vascular dementia due to broader neuropsychiatric benefits and lower cerebrovascular risk than antipsychotics. 3

• Risperidone and olanzapine have three-fold increased stroke risk in elderly dementia patients with pre-existing vascular disease. 3

Parkinson's Disease Dementia

Quetiapine is first-line for patients with Parkinson's disease due to minimal extrapyramidal effects. 5

• Avoid clozapine, ziprasidone, and conventional antipsychotics (especially low- and mid-potency). 5

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Insomnia

Non-Pharmacological First-Line

Behavioral interventions are first-line for insomnia in elderly patients: sleep hygiene, stimulus control, sleep restriction, cognitive therapy for insomnia-related worry. 2

• Morning bright light therapy (2 hours at 3,000–5,000 lux, 09:00–11:00) improves sleep-wake patterns in irregular sleep-wake rhythm disorders. 2
• Establish predictable daily routines, increase daytime physical/social activities (≥30 minutes sunlight exposure), reduce time in bed during the day. 2

Pharmacological Options (When Non-Pharmacological Measures Fail)

Avoid benzodiazepines and Z-drugs (zolpidem) in elderly patients due to high risk of falls, cognitive decline, delirium, and next-morning impairment. 2

• Trazodone (25–100 mg at bedtime) or mirtazapine (7.5–30 mg at bedtime) are preferred if pharmacotherapy is required for insomnia with comorbid depression. 2
• Melatonin should probably not be used in older patients due to poor FDA regulation and inconsistent preparation. 2

Excessive Daytime Somnolence

• Screen for obstructive sleep apnea using Epworth Sleepiness Scale and polysomnography if indicated; initiate CPAP before considering stimulants. 2
• If OSA is excluded and somnolence persists, modafinil (100 mg upon awakening, titrate to 200–400 mg daily) is first-line. 2
• Methylphenidate (2.5–5 mg with breakfast, second dose at lunch) is an alternative. 2
• Caffeine (<300 mg daily, last dose by 4:00 PM) can be used adjunctively. 2

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Critical Safety Principles Across All Psychiatric Medications in Geriatrics

Dosing Principles

"Start low, go slow, and keep it as simple as possible"—begin with 50% of standard adult starting doses and titrate more gradually than in younger adults. 7, 8

• Elderly patients have reduced renal clearance, prolonged drug half-lives, increased drug accumulation, and smaller therapeutic windows even without overt renal disease. 7, 8
• Avoid polypharmacy: multiple psychotropics increase risk of adverse effects (cognitive impairment, falls, QTc prolongation) without demonstrated additive benefit. 3

Medication Interactions

• Review all medications (including over-the-counter) for anticholinergic burden, CYP450 interactions, and QT-prolonging agents before prescribing. 5, 8
• Avoid combining multiple anticholinergic agents (diphenhydramine, hydroxyzine, oxybutynin, cyclobenzaprine)—cumulative burden dramatically increases delirium, falls, and cognitive impairment risk. 3
• Extra caution with SSRIs that inhibit CYP450 (fluoxetine, fluvoxamine, paroxetine) when combined with antipsychotics or other substrates. 5

Monitoring Requirements

• Baseline assessment: vital signs (including orthostatic BP), ECG (if prescribing QT-prolonging agents), renal function, electrolytes, liver function, cognitive status. 1, 2
• Ongoing monitoring: falls risk at every visit, cognitive function, weight/metabolic parameters (with antipsychotics), suicidal ideation (with antidepressants). 3, 1

Common Pitfalls to Avoid

• Do not add medications without first addressing reversible medical causes (pain, infection, metabolic disturbances). 3
• Do not continue medications indefinitely without reassessment—review need at every visit and attempt taper when appropriate. 3
• Do not assume all behavioral symptoms require medication—psychotropics are unlikely to impact unfriendliness, poor self-care, memory problems, repetitive questioning, or wandering. 3
• Do not combine high-dose benzodiazepines with antipsychotics (fatal respiratory depression risk). 3