What is the proper way to take Emend (Aprepitant)?

How to Take Emend (Aprepitant)

For chemotherapy-induced nausea and vomiting, take aprepitant 125 mg orally 1 hour before chemotherapy on Day 1, followed by 80 mg orally once daily on Days 2 and 3, in combination with a 5-HT3 antagonist and dexamethasone. 1

Dosing Regimen for Chemotherapy-Induced Nausea/Vomiting

Day 1 (Day of Chemotherapy)

• Take 125 mg capsule (white and pink) by mouth 1 hour before starting chemotherapy 2
• Administer with a 5-HT3 receptor antagonist (such as ondansetron, granisetron, or palonosetron) 1
• Administer with dexamethasone 12 mg (oral or IV) if using aprepitant 1

Days 2 and 3 (Post-Chemotherapy)

• Take 80 mg capsule (white) once daily 1, 2
• Take 1 hour before chemotherapy if receiving treatment on these days 2
• If no chemotherapy is given on Days 2 and 3, take aprepitant in the morning 2
• Continue dexamethasone 8 mg once daily on these days 1

Administration Instructions

• Swallow capsules whole 2
• May be taken with or without food 2
• Do not crush or open capsules 2

Dosing for Postoperative Nausea/Vomiting (Adults Only)

• Take a single 40 mg capsule within 3 hours before surgery 2
• Follow healthcare provider's instructions about eating and drinking restrictions before surgery 2

Special Considerations for Highly Emetogenic Chemotherapy

For patients receiving highly emetogenic chemotherapy (such as cisplatin or anthracycline combined with cyclophosphamide), the three-drug combination is essential:

• NK1 receptor antagonist (aprepitant): 125 mg Day 1, then 80 mg Days 2-3 1
• 5-HT3 receptor antagonist: Day 1 only 1
• Dexamethasone: 12 mg Day 1, then 8 mg Days 2-4 1

Multi-Day Chemotherapy Regimens

For multi-day chemotherapy regimens likely to be highly emetogenic with significant delayed emesis risk:

• Aprepitant 125 mg on Day 1 with 5-HT3 antagonist and dexamethasone 1
• Aprepitant 80 mg daily on Days 2 and 3 with dexamethasone 1
• Based on phase II data, aprepitant 80 mg may be safely administered on Days 4 and 5 after chemotherapy, though efficacy beyond Day 3 is not yet established 1

Pediatric Dosing (Ages 12-17 Years)

For adolescents who can swallow capsules:

• Day 1: 125 mg capsule 1 hour before chemotherapy 2
• Days 2-3: 80 mg capsule once daily 2
• Take in the morning if no chemotherapy is scheduled 2

Important Drug Interactions and Warnings

Warfarin Interaction

• If taking chronic warfarin therapy, monitor INR closely during the 2-week period after starting aprepitant, particularly at 7-10 days 2
• Aprepitant can affect warfarin metabolism through CYP2C9 induction 2

Hormonal Contraceptive Interaction

• Use effective alternative or backup contraception (condoms and spermicides) during treatment and for 1 month after the last dose 2
• Aprepitant reduces the efficacy of hormonal contraceptives 2

CYP3A4 Interactions

• Aprepitant is both a moderate inhibitor and inducer of CYP3A4 3
• The 125/80 mg regimen produces moderate inhibition of CYP3A4 activity, increasing exposure to CYP3A4 substrates by 2.3-fold on Day 1 and 3.3-fold on Day 5 3
• Exercise caution when coadministering with other CYP3A4 substrates 2, 3

Dexamethasone Dose Adjustment

• The dexamethasone dose is reduced when given with aprepitant (12 mg instead of 20 mg on Day 1) due to pharmacokinetic interaction 1
• This adjustment prevents increased risk of serious infection or febrile neutropenia 4

Common Pitfalls to Avoid

• Do not use aprepitant continuously for chronic nausea/vomiting - it is designed for acute and delayed chemotherapy-induced or postoperative nausea/vomiting only 2
• Do not take if allergic to aprepitant or taking pimozide - serious contraindication 2
• Do not skip the Day 2 and 3 doses - the delayed phase (25-120 hours post-chemotherapy) requires continued coverage, and efficacy is significantly better with the full 3-day regimen 5
• Do not use for breakthrough nausea/vomiting - aprepitant is for prevention, not treatment of existing symptoms 2