Emend works by blocking certain substances in the brain, called neurokinins, which cause nausea and vomiting. When given before chemotherapy, Emend prevents this nausea and vomiting. It does not work against nausea or vomiting that is already occurring.

What medications shouldn’t be taken along with Emend?

You should not take an antipsychotic medication called Orap (pimozide) with Emend, due to the potential for a life-threatening heart problem. Other medication interactions include hormonal birth control and warfarin.

Emend (Aprepitant) Oral: Uses, Side Effects, Dosages

What Is Emend?

Emend (aprepitant) is a medication that helps prevent nausea and vomiting from chemotherapy (a type of cancer treatment) or after surgery. It belongs to a class of medications called substance P/neurokinin-1 (NK1) receptor antagonists, which block the action of a chemical in the nervous system that causes vomiting.

You can take Emend in its oral form as a capsule or solution (liquid), but it is also available as an infusion. This article will focus on the oral form of Emend.

Drug Facts

Generic Name: Aprepitant

Brand Name(s): Emend

Administration Route(s): Oral

Drug Availability: Prescription

Therapeutic Classification: Antiemetic

Available Generically: Yes

Controlled Substance: N/A

Active Ingredient: Aprepitant

Dosage Form(s): Capsule, powder for suspension

What Is Emend Used For?

The Food and Drug Administration (FDA) approved Emend for use along with other anti-nausea, or antiemetic, medications to prevent nausea caused by chemotherapy.

Some chemotherapy medications can cause severe nausea. This can occur immediately after chemotherapy or a few days later. Some other anti-nausea medications help relieve nausea once it occurs. However, Emend helps prevent this nausea before it happens.

Emend can also prevent nausea and vomiting in adults after surgery.

The oral suspension version of Emend is approved for use in people 6 months of age and older, and the capsule form is indicated for people 12 years of age and older.

Verywell / Zoe Hansen

How to Take Emend

When prescribed Emend, follow your healthcare provider’s instructions on when and how to take it. The dosage instructions may vary slightly based on your chemotherapy schedule.

However, you will typically take Emend one hour before chemotherapy on day one. On days two and three, take it either in the morning or one hour before chemotherapy, if receiving chemotherapy on those days. You can take Emend with or without food.

Make sure to swallow the capsules whole—do not break or crush them. If swallowing the capsules is difficult for you, your healthcare provider can prescribe you the liquid form of Emend.

You will also take other anti-nausea medications along with Emend to help it work best. These medications include a steroid called dexamethasone and a medication in the class of 5-HT₃ antagonists. Your healthcare team will give you instructions on how to take these medications.

Storage

Store the Emend capsules at room temperature in their original packaging. The liquid form of Emend should be stored in the refrigerator.

How Long Does Emend Take to Work?

After taking it, Emend works quickly to prevent nausea. It is most effective when you take it as directed for three days and with the other prescribed medications.

What Are the Side Effects of Emend?

This is not a complete list of side effects, and others may occur. A medical professional can advise you on side effects. If you experience other effects, contact your pharmacist or a medical professional. You may report side effects to the FDA at www.fda.gov/medwatch or 800-FDA-1088.

Side effects can occur when taking Emend. It is important to remember that these are possible side effects, not a list of things that will definitely happen. Be sure to tell your healthcare provider about any side effects that persist or worsen.

Common Side Effects

Common side effects include:

Tiredness
Diarrhea
Hiccups
Decreased white blood cells
Weakness or lack of energy
Stomach pain
Increased liver enzyme

Severe Side Effects

In rare cases, Stevens-Johnson syndrome can occur after taking Emend. Stevens-Johnson syndrome is a serious skin reaction that includes symptoms such as severe rash, burning, or itching. If you start to have these symptoms, stop taking Emend and contact the healthcare provider.

Report Side Effects

Emend may cause other side effects. Call your healthcare provider if you have any unusual problems while taking this medication.

If you experience a serious side effect, you or your provider may send a report to the FDA's MedWatch Adverse Event Reporting Program or by phone (800-332-1088).

(800) 332-1088

Dosage: How Much Emend Should I Take?

The dose of this medicine will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of this medicine. If your dose is different, do not change it unless your doctor tells you to do so.

The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.

For oral dosage form (capsules):
- For prevention of nausea and vomiting caused by chemotherapy:
  - Adults and children 12 years of age and older—125 milligrams (mg) 1 hour before chemotherapy (Day 1). Then, 80 mg once in the morning on Days 2 and 3.
  - Children younger than 12 years of age, weighing at least 30 kilograms (kg), and can swallow a capsule—125 mg 1 hour before chemotherapy (Day 1). Then, 80 mg once in the morning on Days 2 and 3.
  - Children younger than 12 years of age weighing less than 30 kg—Use and dose must be determined by your doctor.
- For prevention of nausea and vomiting after surgery:
  - Adults—40 milligrams (mg) within 3 hours before surgery.
  - Children—Use and dose must be determined by your doctor.
For oral dosage form (powder for suspension):
- For prevention of nausea and vomiting caused by chemotherapy:
  - Adults and children 6 months to 11 years of age and cannot swallow the capsule—Dose is based on body weight and must be determined by your doctor. The dose is usually 3 milligrams (mg) per kilogram (kg) of body weight up to a maximum dose of 125 mg taken 1 hour before chemotherapy (Day 1). Then, 2 mg per kg of body weight up to a maximum dose of 80 mg taken once in the morning on Days 2 and 3.
  - Children younger than 6 months of age—Use and dose must be determined by your doctor.

Missed Dose

If you miss a dose of Emend, take it as soon as you remember as long as it is not time for the next dose. Contact your healthcare team if you miss a dose completely.

Overdose: What Happens If I Take Too Much Emend?

If you take too much Emend, contact your healthcare provider to let them know. Taking an excess amount can cause headaches and drowsiness. However, there are no reported cases of severe effects resulting from overdosing on Emend.

What Happens If I Overdose on Emend?

If you think you or someone else may have overdosed on Emend (aprepitant) call a healthcare provider or the Poison Control Center (800-222-1222).

If someone collapses or isn't breathing after taking Emend, call 911 immediately.

911

Precautions

It is very important that your doctor check your progress while you are using this medicine to make sure it is working properly and to check for unwanted effects.

Do not use this medicine if you are also using pimozide (Orap®). Using these medicines together may cause serious unwanted side effects.

This medicine may cause serious allergic reactions, including anaphylaxis. Anaphylaxis can be life-threatening and requires immediate medical attention. Call your doctor right away if you have itching, hives, rash, trouble breathing, trouble swallowing, or any swelling of your hands, face, or mouth while you are using this medicine.

Birth control pills may not work as well while you are using aprepitant. To keep from getting pregnant, use another form of birth control together with your pills while you are using the medicine and for 1 month after your last dose. Other forms of birth control include condoms, diaphragms, or contraceptive foams or jellies.

Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines and herbal or vitamin supplements.

What Are Reasons I Shouldn’t Take Emend?

Do not take Emend if you are allergic to it or any of its ingredients.

Tell your healthcare provider if you are pregnant, plan to become pregnant, or are breastfeeding. There is not enough data to know the risks to the baby when taking Emend while pregnant or nursing.

What Other Medications Interact With Emend?

Certain medications can interact with Emend when taken together.

Emend can reduce how well hormonal birth control medications work for up to 28 days after you take your last dose of Emend. If you take birth control medications, use backup forms of birth control during this time.

Another interaction is with the medication Coumadin (warfarin). Emend can decrease how well Coumadin works. Your healthcare provider may adjust your dose of Coumadin.

You should also not take Emend with an antipsychotic medication called Orap (pimozide), as it can cause a potentially life-threatening heart problem.

Taking Emend with the following medications may also require a dose change:

Medrol (methylprednisolone)
Cardizem CD (diltiazem)
Nizoral (ketoconazole)
Biaxin (clarithromycin)
Sporanox (itraconazole)
Rifadin (rifampin)
Tegretol (carbamazepine)
Dilantin (phenytoin)

What Medications Are Similar?

In addition to Emend, there are other medications in the same drug class that prevent chemotherapy-induced nausea and vomiting.

These medications include:

Akynzeo (netupitant/palonosetron)
Emend (fosaprepitant, injection form of Emend)

These medications are not taken together.

Frequently Asked Questions

What is Emend used for?

Emend is used to prevent immediate and delayed nausea and vomiting caused by chemotherapy. It can also prevent nausea and vomiting that can occur following a surgery.
How does Emend work?

Emend works by blocking certain substances in the brain, called neurokinins, which cause nausea and vomiting. When given before chemotherapy, Emend prevents this nausea and vomiting. It does not work against nausea or vomiting that is already occurring.
What medications shouldn’t be taken along with Emend?

You should not take an antipsychotic medication called Orap (pimozide) with Emend, due to the potential for a life-threatening heart problem. Other medication interactions include hormonal birth control and warfarin.
What are the side effects of Emend?
Side effects of Emend can include:
- Fatigue
- Weakness or lack of energy
- Diarrhea
- Decreased white blood cells
- Hiccups
- Stomach pain
- Increased liver enzyme

How Can I Stay Healthy While Taking Emend?

Nausea and vomiting from chemotherapy can be a very distressing side effect that can lead to poor nutrition and dehydration.

Taking Emend as prescribed, along with other medications to go along with it, can prevent severe nausea and vomiting from chemotherapy. Lifestyle factors, such as good nutrition, may also help with chemotherapy-related side effects.

Alternative approaches to relieving your nausea can be helpful but should be used along with, rather than instead of, your anti-nausea medications.

Be sure to ask your oncology care team any questions you have about taking this medication.

Medical Disclaimer

Verywell Health's drug information is meant for educational purposes only and is not intended as a replacement for medical advice, diagnosis, or treatment from a healthcare professional. Consult your doctor before taking any new medication(s). IBM Watson Micromedex provides some of the drug content, as indicated on the page.