Aprepitant (Emend®)

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About This Drug

Aprepitant is a medication used before chemotherapy to prevent nausea and vomiting (throwing up) during treatment. It is given orally (by mouth).

Possible Side Effects 

  • Decrease in the number of white blood cells. This may raise your risk of infection. 
  • Tiredness and weakness
  • Loose bowel movements (diarrhea)
  • Indigestion
  • Hiccups
  • Pain in your abdomen
  • Dehydration (lack of water in the body from losing too much fluid)
  • Changes in your liver function

Note: Each of the side effects above was reported in 3% or greater of patients treated with aprepitant. Not all possible side effects are included above. 

Warnings and Precautions

  • Allergic reactions, including anaphylaxis are rare but may happen in some patients. Signs of allergic reaction to this drug may be swelling of the face, feeling like your tongue or throat are swelling, trouble breathing, rash, itching, fever, chills, feeling dizzy, and/or feeling that your heart is beating fast or not normal way. If this happens, do not take another dose of this drug. You should get urgent medical treatment. 

How to Take Your Medication

  • Capsule: Swallow the medicine whole with or without food.
  • Oral Suspension: The suspension will be prepared by your healthcare provider. The medication can be left at room temperature for 3 hours. When ready to use, insert dispenser inside the right or left inner cheek, dispense slowly. Must be used within 72 hours of preparation. 
  • Storage: Store the capsules at room temperature. Store the oral suspension in the refrigerator. 

Treating Side Effects

  • To decrease infection, wash your hands regularly. 
  • Avoid close contact with people who have a cold, the flu, or other infections. 
  • Take your temperature as your doctor or nurse tells you, and whenever you feel like you may have a fever.
  • Manage tiredness by pacing your activities for the day. 
  • Be sure to include periods of rest between energy-draining activities. 
  • Drink plenty of fluids (a minimum of eight glasses per day is recommended).
  • If you throw up or have loose bowel movements, you should drink more fluids so that you do not become dehydrated (lack water in the body from loosing too much fluid). 
  • If you get diarrhea, eat low-fiber foods that are high in protein and calories and avoid foods that can irritate your digestive tracts or lead to cramping.
  • Ask your nurse or doctor about medicine that can lessen or stop your diarrhea. 
  • Keeping your pain under control is important to your well-being. Please tell your doctor or nurse if you are experiencing pain. 

Food and Drug Interactions

  • Do not eat grapefruit or drink grapefruit juice while taking this medicine. Grapefruit and grapefruit juice may raise the levels of aprepitant in your body. This could make side effects worse. 
  • Check with your doctor or pharmacist about all other prescription medicines and dietary supplements you are taking before starting this medicine as there are known drug interactions with aprepitant. Also, check with your doctor or pharmacist before starting any new prescription or over-the-counter medicines, or dietary supplement to make sure that there are no interactions. 
  • Avoid the use of St. John's Wort while taking aprepitant as this may lower the levels of the drug in your body, which can make it less effective. 
  • There are known interactions of aprepitant with blood thinning medicine such as warfarin. Ask your doctor what precautions you should take. 
  • Birth control pills (oral contraceptives) may not be effective with this medication, it is recommended to use another form of birth control (such as a condom) during treatment and for 1 month after treatment. 

When to Call the Doctor

Call your doctor or nurse if you have any of these symptoms and/or any new or unusual symptoms:

  • Fever of 100.5 F(38 C) or higher
  • Chills
  • Fatigue that interferes with your daily activities 
  • Lasting loss of appetite or rapid weight loss of five pounds in a week
  • Loose bowel movements (diarrhea) 4 times a day or loose bowel movements with lack of strength or a feeling of being dizzy
  • Pain that does not go away, or is not relieved by prescribed medicines
  • Signs of allergic reaction: swelling of the face, feeling like your tongue or throat are swelling, trouble breathing, rash, itching, fever, chills, feeling dizzy, and/or feeling that your heart is beating in a fast or not normal way
  • Signs of possible liver problems: dark urine, pale bowel movements, bad stomach pain, feeling very tired and weak, unusual itching, or yellowing of the eyes or skin
  • If you think you may be pregnant

Reproduction Warnings

  • Pregnancy warning: This drug can have harmful effects on the unborn baby. Women of child bearing potential should use effective non-hormonal methods of birth control during your cancer treatment and for at least 1 month after treatment. Let your doctor know right away if you think you may be pregnant. Birth control pills (oral contraceptives) may not be effective with this medication.
  • Breastfeeding warning: It is not known if this drug passes into breast milk. For this reason, women should talk to their doctor about the risks and benefits of breast feeding during treatment with this drug because this drug may enter the breast milk and cause harm to a breast feeding baby. 
  • Fertility warning: This drug is not expected to affect your ability to have children in the future. Human fertility studies have not been done with this drug.

Revised September 2017