Adult Starting and Maintenance Doses for Psychiatric Medications
Based on the available guideline evidence, here are the recommended adult starting and typical maintenance doses for key psychiatric medications:
Antipsychotics
First-Generation (Typical) Antipsychotics
Haloperidol:
- Starting dose: 0.5–1 mg PO or SC stat 1
- PRN dosing: 0.5–1 mg PO or SC every 1 hour as needed 1
- Maintenance: Give every 8–12 hours if scheduled dosing required 1
- Use lower doses (0.25–0.5 mg) in older or frail patients 1
Chlorpromazine:
- Starting dose: 12.5–25 mg PO or PR stat 1
- Maintenance: Give every 6–12 hours if scheduled dosing required 1
- In older patients, use doses in the lower range 1
Second-Generation (Atypical) Antipsychotics
Risperidone:
- Starting dose: 0.25–0.5 mg PO daily at bedtime (elderly/dementia) 2; 0.5 mg PO stat (general adult) 1
- Maximum/Maintenance: 2–3 mg daily, usually divided twice daily 2; up to every 12 hours if scheduled 1
- Extrapyramidal symptoms may occur at 2 mg/day 2
Olanzapine:
- Starting dose: 2.5–5 mg PO or SC stat 1; 2.5 mg daily at bedtime (elderly) 2
- Maintenance: 2.5–5 mg PO or SC daily, usually at bedtime if scheduled 1; maximum 10 mg daily in divided doses 2
- Reduce dose in older patients and those with hepatic impairment 1
Quetiapine:
- Starting dose: 12.5 mg twice daily (elderly) 2; 25 mg immediate-release PO stat (general adult) 1
- Maximum/Maintenance: 200 mg twice daily 2; give every 12 hours if scheduled 1
- More sedating; beware of transient orthostasis 2
Aripiprazole:
- Starting dose: 5 mg PO or IM (immediate-release) stat 1
- Maintenance: Give every 24 hours if scheduled 1
- Long-acting injectable (AOM 400): 400 mg is both the starting and maintenance dose, with 14-day overlap of oral aripiprazole (10–15 mg/day) or previous antipsychotic 3
Antidepressants
Selective Serotonin Reuptake Inhibitors (SSRIs)
Fluoxetine:
- Starting dose: 10 mg every other morning 2
- Maintenance: 20 mg every morning 2
- Very long half-life; activating 2
Paroxetine:
- Starting dose: 10 mg daily 2
- Maintenance: 40 mg daily (morning or evening) 2
- Less activating but more anticholinergic than other SSRIs 2
Sertraline:
- Starting dose: 25–50 mg daily 2, 4
- Maintenance: 50–200 mg daily (morning or evening) 2, 4
- 50 mg daily is the optimal dose for most patients when considering both efficacy and tolerability 5
- Well tolerated; less effect on metabolism of other medications 2
Citalopram:
Escitalopram:
Fluvoxamine:
Serotonin-Norepinephrine Reuptake Inhibitors (SNRIs)
Venlafaxine:
- Starting dose: 37.5 mg once or twice daily 6, 4
- Titration: Increase by 75 mg each week 6
- Maintenance: 150–225 mg daily 6, 4
- Requires 2–4 weeks to titrate to efficacious dosage 6
Duloxetine:
- Starting dose: 30 mg once daily 6, 4
- Titration: Increase to 60 mg once daily after 1 week 6
- Maintenance: 40–120 mg daily 6, 4
Tricyclic Antidepressants (TCAs)
Nortriptyline:
- Starting dose: 10 mg at bedtime 2, 4
- Maintenance: 25–150 mg daily, typically 40 mg daily given twice daily 2, 4
- Therapeutic blood level "window" of 50–150 ng/mL 2
- More sedating; useful in agitated depression with insomnia 2
Desipramine:
- Starting dose: 10–25 mg in the morning 2, 4
- Maintenance: 100–300 mg in the morning 2, 4
- Tends to be activating; lower risk for cardiotoxic, hypotensive, and anticholinergic effects 2
Amitriptyline:
Other Antidepressants
Bupropion:
- Starting dose: 37.5 mg every morning, then increase by 37.5 mg every 3 days 2, 4
- Maintenance: 100–400 mg daily (SR formulation), typically 150 mg twice daily 2, 4
- Activating; give second dose before 3 PM to minimize insomnia 2
Mirtazapine:
- Starting dose: 7.5 mg at bedtime 2, 4
- Maintenance: 15–45 mg at bedtime, typically 30 mg 2, 4
- Promotes sleep, appetite, and weight gain 2
Trazodone:
- Starting dose: 25–50 mg daily 2, 4
- Maintenance: 50–400 mg daily in divided doses, maximum 200–400 mg 2, 4
Nefazodone:
Mood Stabilizers
Lithium:
- Starting dose: 150 mg daily 2
- Maintenance: 150–300 mg daily 2
- Target blood levels: 0.2–0.6 mEq/L (0.2–0.6 mmol/L) 2
- In elderly patients, these lower levels are generally adequate 2
Carbamazepine:
- Starting dose: 100 mg twice daily 2
- Titration: Titrate to therapeutic blood level (4–8 mcg/mL) 2
- Monitor CBC and liver enzymes regularly 2
Divalproex sodium:
- Starting dose: 125 mg twice daily 2
- Titration: Titrate to therapeutic blood level (40–90 mcg/mL) 2
- Generally better tolerated than carbamazepine 2
Calcium Channel α2δ Ligands (for Neuropathic Pain)
Gabapentin:
- Starting dose: 100–300 mg at bedtime or 100–300 mg three times daily 6
- Titration: Increase by 100–300 mg every 1–7 days as tolerated 6
- Maximum: 3600 mg daily in 3 divided doses 6
- Reduce dose if impaired renal function 6
- Adequate trial requires 3–8 weeks for titration plus 2 weeks at maximum dose 6
Pregabalin:
- Starting dose: 50 mg three times daily or 75 mg twice daily 6
- Titration: Increase to 300 mg/day after 3–7 days, then by 150 mg/day every 3–7 days as tolerated 6
- Maximum: 600 mg daily (200 mg three times daily or 300 mg twice daily) 6
- Reduce dose if impaired renal function 6
- Adequate trial: 4 weeks 6
Important Clinical Considerations
Elderly Patients
- Start with approximately 50% of the standard adult starting dose for most psychotropic medications 4
- Titrate more slowly due to increased risk of adverse drug reactions 4
- Lower doses are often sufficient (e.g., 0.25–0.5 mg haloperidol, 2.5 mg olanzapine) 1
Duration of Treatment
- First episode of major depression: Continue treatment for 4–12 months after remission 4
- Recurrent depression: May benefit from prolonged treatment 4
- Maintenance strategies: Continuing the same dose or reducing dose show good performance in efficacy, tolerability, and acceptability 7
Monitoring
The evidence emphasizes that dose titration should be gradual, typically increasing by increments of the initial dose every 5–7 days until therapeutic benefits or significant side effects appear 2. For antidepressants, a full therapeutic trial requires at least 4–8 weeks 2.