Emendfosaprepitant
How it works
Blocks substance P at NK1 receptors in the chemoreceptor trigger zone. Adds to the 5-HT3 antagonist + dexamethasone backbone for highly emetogenic chemotherapy (HEC).
Strong CYP3A4 inhibitor on D1 (moderate D2–D3). Dose-adjust concurrent dexamethasone per guideline (usually 50% reduction when combined). Especially relevant for mFFX regimens.
Dosing
Typical doses
- 125 mg PO 1 h before chemo, D1
- 80 mg PO D2 + D3
- Fosaprepitant 150 mg IV single dose D1 (alternative)
Schedule
- D1–D3 of HEC cycle (mFFX); D1 only for MECcycle_linked
Side Effects
- •Fatigue / asthenia
- •Constipation, diarrhoea
- •Headache, hiccups
- CYP3A4 inhibition — interaction with dexamethasone, warfarin, midazolam, oral contraceptives
- Rare hepatotoxicity — monitor LFTs
Monitoring
- Review concurrent CYP3A4 substrates — may need dose adjustments