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Fosaprepitant (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 this medicine if you had an allergic reaction to fosaprepitant, aprepitant, or polysorbate 80.

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 infusion may take up to 30 minutes.
  • This medicine is usually given on the first day of your cancer treatment as part of a 3-day regimen 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 cisapride or pimozide.
  • Some foods and medicines can affect how aprepitant works. Tell your doctor if you are using diltiazem, rifampin, tolbutamide, a blood thinner (such as warfarin), a steroid (such as dexamethasone, methylprednisolone), medicine for seizures (such as carbamazepine, phenytoin), a sedative (such as alprazolam, midazolam, triazolam), medicine for depression (such as nefazodone, paroxetine), medicine to treat infections (such as clarithromycin, itraconazole, ketoconazole, troleandomycin), medicine to treat HIV/AIDS (such as nelfinavir, ritonavir), or cancer medicine (such as ifosfamide, imatinib, irinotecan, vinblastine, vincristine).

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 during treatment and for 1 month after your last treatment. Other forms include condoms, a diaphragm, and contraceptive foam or jelly.
  • If you are also taking a blood thinner (such as warfarin), your doctor will need to check your blood after you receive this medicine.

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
  • 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:

  • Constipation, diarrhea, loss of appetite
  • Headache
  • Tiredness or weakness

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: 3/28/2016
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