What is the best medication for treating psychosis?

Best Medications for Psychosis

Atypical antipsychotics are the first-line treatment for psychosis, with risperidone 2 mg/day or olanzapine 7.5-10.0 mg/day being the recommended initial target doses for most patients. 1

Initial Medication Selection

• Atypical antipsychotics are preferred over typical antipsychotics due to better tolerability and fewer extrapyramidal side effects, even though both may be equally efficacious in reducing positive psychotic symptoms 1
• Recommended initial target doses for first-episode psychosis:
  • Risperidone 2 mg/day 1
  • Olanzapine 7.5-10.0 mg/day 1
• Low doses should be used initially, with careful titration to minimize side effects 1
• Extrapyramidal side effects should be avoided to encourage future medication adherence 1

Dosing Considerations

• After initial titration, antipsychotic doses should only be increased at widely spaced intervals (usually 14-21 days) if response has been inadequate 1
• Maximum recommended doses for first-episode psychosis:
  • Risperidone 4 mg/day 1
  • Olanzapine 20 mg/day 1
  • Haloperidol 4-6 mg/day (if typical antipsychotics are used) 1
• Dose increases should stay within the limits of sedation and extrapyramidal side effects 1

Treatment Algorithm

1. First-line treatment: Start with an atypical antipsychotic (risperidone 2 mg/day or olanzapine 7.5-10 mg/day) 1, 2
2. Inadequate response: If positive psychotic symptoms persist after an adequate trial (4-6 weeks), consider switching to another atypical antipsychotic 1
3. Treatment resistance: If symptoms persist after trials of two first-line atypical antipsychotics (around 12 weeks total), review reasons for treatment failure 1
4. Clozapine consideration: For treatment-resistant psychosis, clozapine may be considered, though it requires close monitoring due to risk of agranulocytosis 1, 3

Special Considerations

• For acute agitation, intramuscular formulations may be needed for rapid control of symptoms 1, 4
• When psychosis is due to neurological conditions:
  • For Alzheimer's disease: risperidone 0.5-3 mg/day is first-line 5
  • For Parkinson's disease: first reduce anti-parkinsonian medications if possible, then consider quetiapine or clozapine 5
  • For epilepsy: maximize anticonvulsant therapy first, then consider low-dose atypical antipsychotics 5

Monitoring and Follow-up

• Monitor for common side effects including:
  • Weight gain and metabolic changes 6
  • Extrapyramidal symptoms 1
  • Sedation 1
• Maintain continuity of care with the same treating clinicians for at least the first 18 months of treatment 1
• Include families in the treatment plan and provide them with emotional support and practical advice 1
• Develop supportive crisis plans to facilitate recovery and treatment acceptance 1

Common Pitfalls to Avoid

• Using excessive doses in first-episode psychosis, which increases side effects without improving efficacy 1, 6
• Failing to rule out secondary causes of psychosis (medical conditions, substance use) before initiating psychiatric treatment 2, 3
• Neglecting psychosocial interventions, which are essential components of comprehensive treatment 1
• Changing medications too quickly before an adequate trial period (4-6 weeks) 1
• Overlooking the importance of family involvement in the treatment process 1