Skip to content
ClinCalc Pro
Menu
Calculators Drugs Pathways AI Dx Donate Get the App
5-HT2 antagonist (antihistamine)

Pizotifen

Brand names: Sanomigran

Pizotifen is an antihistamine and serotonin (5-HT2) antagonist used for the prophylaxis of migraine, including in children, and of recurrent vascular headache.

Dosing — being independently re-sourced

ClinCalc Pro is rebuilding its dose data from primary open sources — the manufacturer SmPC (eMC), the WHO Model Formulary and other official references — under clinician review. This drug's structured dose is not yet published here. Confirm all doses against the product SmPC and your local formulary before prescribing.

Clinical monograph

How it works

It blocks serotonin 5-HT2, histamine and muscarinic receptors, and this antiserotonergic action is thought to underlie its migraine-preventive effect.

Prescribing in practice

  • Weight gain and increased appetite are common and frequently limit its long-term use.
  • It has sedative and antimuscarinic properties, so use caution in glaucoma, urinary retention, and where drowsiness would be hazardous.
  • Doses are often weighted toward bedtime to reduce daytime sedation, and it should not be stopped abruptly after prolonged use.

Monitoring

Monitor weight, appetite, and the degree of sedation, alongside the frequency and severity of migraine attacks to judge benefit.

Counselling the patient

  • This medicine is taken to prevent migraines, not to treat an attack once it has started.
  • It commonly causes drowsiness and increased appetite with weight gain; taking more of the dose at night can help with sleepiness.
  • For children, follow the dose in a children's formulary exactly as prescribed.

Evidence & guidelines

Pizotifen is a long-established migraine prophylactic recognised in NICE guidance, with efficacy supported by clinical experience and trial data.

Reference: NICE CG150; Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. Monograph status: clinician-reviewed (2026-07-04).

Related

Curated clinical cross-links plus same-class fallbacks.

Calculators
Pathways