Health Guide

Fosaprepitant (By injection)

Fosaprepitant Dimeglumine (fos-a-PRE-pi-tant dye-MEG-loo-meen)

Prevents nausea and vomiting caused by cancer treatment (chemotherapy).

Brand Name(s):


There may be other brand names for this medicine.

When This Medicine Should Not Be Used:

This medicine is not right for everyone. You should not receive it if you had an allergic reaction to fosaprepitant or aprepitant.

How to Use This Medicine:


  • Your doctor will prescribe your dose and schedule. This medicine is given through a needle placed in a vein.
  • A nurse or other health provider will give you this medicine. The medicine must be given slowly, so the needle will have to stay for at least 30 minutes.
  • This medicine is usually given on the first day of your cancer treatment along with other medicines. This medicine is not for long-term use, but you may need to use it again if you have more cancer treatments.
  • Read and follow the patient instructions that come with this medicine. Talk to your doctor or pharmacist if you have any questions.

Drugs and Foods to Avoid:

Ask your doctor or pharmacist before using any other medicine, including over-the-counter medicines, vitamins, and herbal products.

  • You should not receive this medicine together with pimozide.
  • Tell your doctor about all cancer medicines you take. Some cancer medicines, including ifosfamide, vinblastine, and vincristine, can interact with this medicine and cause side effects.
  • Also tell your doctor if you are using any of the following:
    • Carbamazepine, clarithromycin, dexamethasone, diltiazem, itraconazole, ketoconazole, methylprednisolone, nefazodone, nelfinavir, phenytoin, rifampin, ritonavir, troleandomycin
    • Blood thinner (including warfarin)
    • Sedative (including alprazolam, midazolam, triazolam)

Warnings While Using This Medicine:

  • Tell your doctor if you are pregnant or breastfeeding, or if you have liver disease.
  • Birth control pills may not work as well while you are receiving this medicine. Use another form of birth control (including condoms, spermicides) during treatment and for 1 month after your last dose.
  • Your doctor will check your progress and the effects of this medicine at regular visits. Keep all appointments.

Possible Side Effects While Using This Medicine:

Call your doctor right away if you notice any of these side effects:

  • Allergic reaction: Itching or hives, swelling in your face or hands, swelling or tingling in your mouth or throat, chest tightness, trouble breathing
  • Blistering, peeling, red skin rash
  • Fever, chills, headache, nausea, vomiting
  • Pain, itching, burning, swelling, or a lump under your skin where the needle is placed
  • Warmth or redness in your face, neck, arms, or upper chest

If you notice these less serious side effects, talk with your doctor:

  • Diarrhea
  • Tiredness

If you notice other side effects that you think are caused by this medicine, tell your doctor

Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088

Last Updated: 7/4/2018
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