What is the starting dose of Risperdal (risperidone) for schizophrenia?

Starting Dose of Risperidone for Schizophrenia

For adults with schizophrenia, start risperidone at 2 mg per day (either once daily or divided into twice daily dosing), then titrate gradually to a target dose of 4 mg per day. 1

Adult Dosing Algorithm

Initial Dosing

• Start at 2 mg per day (can be given once daily or divided twice daily) 1
• The FDA label explicitly recommends this 2 mg starting dose for adults with schizophrenia 1
• Titrate in increments of 1-2 mg per day at intervals of 24 hours or greater, though slower titration may be more appropriate in many patients 1

Target Dose

• Aim for 4 mg per day as the optimal target dose for most patients 2, 3
• The effective dose range is 4-16 mg per day, but doses above 6 mg per day show no additional efficacy and significantly increase extrapyramidal symptoms 1, 4
• PET imaging studies demonstrate that 4 mg per day achieves optimal D2 receptor occupancy (70-80%) with minimal risk of extrapyramidal side effects 5

Key Dosing Principles

• Do not routinely target 6 mg per day, despite this being used in early clinical trials 3, 5
• The original 6 mg target was based on studies of chronically ill, hospitalized, treatment-resistant patients and is unnecessarily high for most patients 3
• Doses above 6 mg per day carry increased risk of extrapyramidal symptoms without additional therapeutic benefit 2, 6, 4

Special Populations

First-Episode Psychosis

• Maximum recommended dose is 4 mg per day 2, 6
• Start at 2 mg per day with slower titration than chronic patients 1
• Initial target should be 2 mg per day, with dose increases only at widely spaced intervals (14-21 days) if response is inadequate 2
• Higher doses in first-episode patients increase extrapyramidal symptoms and reduce medication adherence 2

Adolescents (13-17 years)

• Start at 0.5 mg once daily (morning or evening) 1
• Titrate in increments of 0.5-1 mg per day at intervals of 24 hours or greater 1
• Target dose is 3 mg per day, with an effective range of 1-6 mg per day 1
• No additional benefit observed above 3 mg per day, and higher doses increase adverse events 1

Elderly Patients

• Start at 0.5 mg twice daily 2, 6
• Use the lowest effective dose and titrate more slowly than in younger adults 2, 6
• Risk of extrapyramidal symptoms increases significantly above 6 mg per 24 hours 2

Severe Renal or Hepatic Impairment

• Start at 0.5 mg twice daily 1
• May increase to dosages above 1.5 mg twice daily at intervals of one week or longer 1

Common Pitfalls to Avoid

• Avoid starting at 6 mg per day: This dose was based on early trials with treatment-resistant patients and causes unnecessarily high D2 receptor occupancy (>80%), leading to extrapyramidal symptoms 5
• Avoid rapid titration: Slower dose increases allow better tolerability assessment and reduce side effects 1, 3
• Don't exceed 6 mg per day without clear justification: Higher doses don't improve efficacy but significantly increase adverse effects 2, 6, 4
• Don't use the same starting dose across all populations: Elderly, first-episode, and adolescent patients require lower starting doses 2, 1

Maintenance Considerations

• Once-daily dosing is as effective as twice-daily administration and may improve adherence 1, 7
• Patients experiencing persistent somnolence may benefit from splitting the daily dose into twice-daily administration 1
• After acute response, maintain patients on their effective dose and periodically reassess the need for continued treatment 1