What Is Emend? Uses, Dosage, and What You Need to Know in 2026

Emend (aprepitant) is an antiemetic—a medication that prevents nausea and vomiting—specifically designed for people undergoing certain types of chemotherapy or surgery. It belongs to a class called neurokinin-1 (NK1) receptor antagonists and was the first of its kind to receive FDA approval in 2003. This guide covers everything you need to know as a patient.

What Is Emend Used For?

Emend has two FDA-approved uses:

Chemotherapy-Induced Nausea and Vomiting (CINV): Emend is prescribed before and after chemotherapy cycles to prevent both acute nausea (within 24 hours) and delayed nausea (days 2-5) caused by highly and moderately emetogenic chemotherapy. It's typically used in combination with a 5-HT3 antagonist (like ondansetron) and a steroid (dexamethasone).

Postoperative Nausea and Vomiting (PONV): The 40 mg capsule is used to prevent nausea and vomiting after surgery involving general anesthesia.

Emend is a preventive medication—it will not treat nausea or vomiting that has already started. It must be taken before chemotherapy or surgery begins to be effective.

What Forms Does Emend Come In?

40 mg capsule: For PONV prevention; taken within 3 hours before induction of anesthesia

80 mg capsule: The second and third day doses in the CINV regimen; taken in the morning on Days 2 and 3

125 mg capsule: The starting dose for CINV; taken 1 hour before chemotherapy on Day 1

Powder for oral suspension (25 mg/mL when reconstituted): Available for patients 6 months and older who cannot swallow capsules; prepared by a healthcare provider

There is also an intravenous form called fosaprepitant (Emend for Injection), which converts to aprepitant in the body after administration. It's given only on Day 1 at a dose of 150 mg IV.

Who Takes Emend?

Emend is prescribed for:

Adults receiving highly or moderately emetogenic chemotherapy (including cisplatin-based regimens, many breast cancer regimens, and others)

Children 12 years and older (capsules), or children 6 months and older (oral suspension) undergoing emetogenic chemotherapy

Adults at risk for postoperative nausea and vomiting after general anesthesia

How Do You Take Emend for Chemotherapy?

The standard CINV regimen is a 3-day course:

Day 1: 125 mg taken 1 hour before chemotherapy (combined with ondansetron and dexamethasone)

Day 2: 80 mg taken in the morning (even if you don't have chemotherapy that day)

Day 3: 80 mg taken in the morning

Emend capsules can be taken with or without food. Do not open or chew the capsules—swallow them whole. Store capsules at room temperature between 68°F-77°F (20°C-25°C).

Is Emend a Controlled Substance?

No. Emend (aprepitant) is not a controlled substance. It has no abuse or dependency potential. It can be prescribed and refilled like any standard prescription medication without special DEA restrictions.

Is a Generic Version Available?

Yes. Generic aprepitant is available from multiple manufacturers and is FDA-approved as bioequivalent to brand-name Emend. The generic is therapeutically identical and significantly less expensive. Most insurance plans prefer (or require) the generic version.

Key Things to Know Before Taking Emend

Hormonal birth control: Emend reduces the effectiveness of hormonal contraceptives. Use backup non-hormonal contraception during treatment and for 28 days afterward.

Pimozide (Orap) is absolutely contraindicated with Emend.

Dexamethasone dose must be reduced by about 50% (oral) or 25% (IV) when taken alongside Emend.

Warfarin users need INR monitoring 7-10 days after each Emend course.

Finding Emend at a Pharmacy Near You

Emend isn't always stocked at every retail pharmacy. If you're having trouble finding it before your next treatment cycle, medfinder can help. medfinder calls pharmacies near you to check which ones have your medication in stock, then texts you the results.

Want to understand exactly how Emend works at the molecular level? Read our guide: How Does Emend Work? Mechanism of Action Explained in Plain English.