Cyproheptadine Dosage and Usage Guidelines
Cyproheptadine dosage should be individualized based on age, weight, and clinical response, with adults typically requiring 4-20 mg daily divided into 2-3 doses, not exceeding 0.5 mg/kg/day. 1
Adult Dosing
- Initial dose: 4 mg (1 tablet) three times daily, adjusted according to patient response 1
- Therapeutic range: 4-20 mg per day, with most patients requiring 12-16 mg daily 1
- Maximum daily dose: 32 mg per day, though this is rarely needed for adequate symptom relief 1
- For nightmare disorder treatment: 2-6 mg nightly, with effects potentially seen within a few days 2
- For serotonin syndrome: 4-8 mg orally, which may be repeated if symptoms persist 3
Pediatric Dosing
- Ages 2-6 years: Approximately 0.25 mg/kg/day or 8 mg per square meter of body surface area 1
- Ages 7-14 years: 4 mg (1 tablet) two or three times daily 1
- Maximum: 16 mg per day 1
- For serotonin syndrome in pediatric patients: 0.25 mg/kg per day 4
Clinical Applications
Appetite Stimulation
- Effective for promoting weight gain in both children and adults with poor appetite 5, 6
- In a large randomized controlled trial, cyproheptadine showed significant improvement in appetite scores compared to placebo (difference +0.38; 95% CI, -0.73 to -0.04; p=0.0307) 5
- Has demonstrated effectiveness in cancer-related cachexia in children, with an average weight gain of 2.6 kg after 4 weeks of treatment 7
Nightmare Disorder
- For PTSD-related nightmares: Doses ranging from 2-6 mg nightly have shown efficacy in eliminating nightmares in some patients 2
- Higher doses (16-24 mg) have been used in combat-related PTSD 2
- Response typically occurs within days to weeks, with complete remission or significant reduction in nightmares within 3-4 weeks in responsive patients 2
Serotonin Syndrome
- Used as an adjunct to supportive care for serotonin syndrome 3, 8
- Dosage: 4-8 mg orally, with potential resolution of signs within 2 hours of administration 3
Side Effects and Precautions
- Most common adverse effect: Sedation/drowsiness 5, 6
- Other potential side effects include:
- Use with caution in older adults due to increased sensitivity to anticholinergic effects and higher risk of adverse events 2
- May worsen narrow-angle glaucoma, prostatic hypertrophy, and cognitive impairment 2
Clinical Pearls
- For appetite stimulation, benefits may be limited in progressive disease states like advanced cancer or HIV 6
- When used for serotonin syndrome, cyproheptadine should be considered an adjunct to supportive care rather than definitive treatment 3, 8
- Tablets can be divided for smaller doses and crushed for administration via nasogastric tube if needed 4
- Monitor for sedation, especially when initiating therapy or adjusting doses 5, 6
- The benefits of cyproheptadine for serotonin syndrome remain uncertain, with recommendations suggesting its use should be based on diagnostic criteria, symptom severity, and in conjunction with other supportive measures 8