Amisulpiride Starting Dose
For acute exacerbations of schizophrenia with predominantly positive symptoms, start amisulpiride at 800 mg/day from day one, as this provides maximal efficacy without significant additional side effects compared to lower starting doses. 1, 2
Dose Selection Based on Clinical Presentation
Acute Psychosis with Positive Symptoms
- Initiate at 800 mg/day immediately without titration for patients experiencing acute exacerbations with hallucinations, delusions, or severe agitation 1, 2
- The 400-800 mg/day range is acceptable, but evidence supports starting at the higher end (800 mg/day) to achieve faster response rates—68.4% of patients achieved ≥30% symptom reduction by week 4 with 800 mg/day versus only 40% with 400 mg/day 2
- No gradual titration is required; amisulpiride can be initiated at target therapeutic dose from day one with low risk of extrapyramidal symptoms 1
- Maximum doses up to 1200 mg/day may be used if needed 3, 4
Predominantly Negative Symptoms
- Start at 50-100 mg/day for patients with primary deficit symptoms (apathy, social withdrawal, blunted affect) where positive symptoms are minimal or absent 1, 3, 5
- Use 50 mg twice daily dosing when negative symptoms predominate 1
- The effective range for negative symptoms is 50-300 mg/day, with 100 mg/day being the most commonly studied dose 3, 5, 6
- At these low doses, amisulpiride preferentially blocks presynaptic dopamine autoreceptors to enhance dopaminergic transmission, which differs mechanistically from its action at higher doses 3, 6
Administration Strategy
Dosing Schedule
- For acute positive symptoms (800 mg/day): can be given as a single daily dose or divided into twice-daily administration 3
- For negative symptoms (50-100 mg/day): use twice-daily dosing (e.g., 50 mg BID) 1
Duration of Adequate Trial
- Maintain therapeutic dose for at least 6 weeks before determining treatment response 7
- Most non-responders within the first 6 weeks will not respond at later time points 7
Common Pitfalls to Avoid
- Do not start with unnecessarily low doses in acute psychosis—starting at 400 mg/day instead of 800 mg/day delays response without reducing side effects 2
- Do not confuse dosing for positive versus negative symptoms—using high doses (800 mg/day) for predominantly negative symptoms will not provide additional benefit and increases side effect risk 3, 5
- Do not assume gradual titration is needed—unlike many antipsychotics, amisulpiride can be started at full therapeutic dose without increased extrapyramidal symptoms 1, 2
- Monitor for hyperprolactinemia (occurs in ~86% of patients) and extrapyramidal symptoms (occurs in ~35% of patients), though EPS risk remains lower than conventional antipsychotics 2