Section 02 · Monograph
Cyproheptadine
Reviewed Nov 2026FDA label
PeriactinH1/5-HT2 antagonist
- Forms
- Tab: 4mg | Syrup: 2mg/5mL
- Dose
- Migraine prevention (off-label): pediatric 0.25-0.5mg/kg/day divided; adults 4-12mg/day
- MOA
- Antihistamine with serotonin 5-HT2 antagonism
Indications
- Allergic rhinitis, urticaria and other allergic conditionsFDA-labeled
Off-Label Uses
- Migraine prevention, especially in childrenOff-label
- Serotonin syndrome adjunct and appetite stimulationOff-label
Mechanism of Action
- First-generation H1 antihistamine with potent 5-HT2 serotonin antagonism and anticholinergic activity
Full Dosing
Adult / usual
- Titrate from a low bedtime dose to limit sedation
Pediatric
- Migraine prevention (off-label): pediatric 0.25-0.5mg/kg/day in 2-3 divided doses; adults 4-12mg/day, often given at bedtime
Contraindications
- Newborn or premature infants and nursing mothers
- MAO inhibitor therapy
- Angle-closure glaucoma, stenosing peptic ulcer, symptomatic prostatic hypertrophy, bladder neck obstruction, pyloroduodenal obstruction
- Elderly or debilitated patients
Drug Interactions
- MAOIs prolong anticholinergic effects
- Additive sedation with alcohol and CNS depressants
- May reduce the effect of SSRIs (serotonin antagonism)
Adverse Effects
- Sedation, dizziness
- Weight gain and increased appetite
- Dry mouth, urinary retention, blurred vision
- Paradoxical excitation in young children
Monitoring Parameters
- Sedation and school/work function
- Weight and growth in children
- Anticholinergic burden in older adults
Pregnancy & Lactation
- Limited data; use if benefit justifies risk
- Contraindicated in nursing mothers per label