Fosaprepitant (Injection)


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

Used with other medicines to prevent 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

You should not receive this medicine if you have had an allergic reaction to fosaprepitant, aprepitant, or polysorbate 80. You should not receive this medicine if you are also using cisapride (Propulsid®) or pimozide (Orap®). Fosaprepitant may cause serious or life-threatening problems if used together with these medicines.

How to Use This Medicine


  • Your doctor will prescribe your exact dose and tell you how often it should be given. This medicine is given through a needle placed in one of your veins.
  • A nurse or other trained health professional will give you this medicine.
  • This medicine is usually given on the first day of your cancer treatment as part of a three-day regimen along with other medicines. Fosaprepitant is not for long-term use, but you may need to use this medicine again if you have more cancer treatments in the future.
  • This medicine comes with patient instructions. Read and follow these instructions carefully. Ask 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.

  • There are many other medicines that you should not use together with fosaprepitant. These include prescription and nonprescription medicines, vitamins, and herbal supplements. Make sure your doctor knows about all the other medicines that you use.
  • Make sure your doctor knows if you are also using dexamethasone (Decadron®), diltiazem (Cartia®, Tiazac®), methylprednisolone (Medrol®), rifampin (Rifadin®, Rimactane®), tolbutamide (Orinase®), a blood thinner (such as warfarin, Coumadin®, Jantoven®), medicine for seizures (such as carbamazepine, phenytoin, Dilantin®, or Tegretol®), a sedative (such as alprazolam, midazolam, triazolam, Halcion®, Versed®, or Xanax®), medicine for depression (such as nefazodone, paroxetine, Paxil®, or Serzone®), medicine to treat fungal infections (such as itraconazole, ketoconazole, Nizoral®, or Sporanox®), medicine to treat bacterial infections (such as clarithromycin, troleandomycin, or Biaxin®), or medicine to treat HIV/AIDS (such as nelfinavir, ritonavir, Norvir®, or Viracept®).
  • Birth control pills may not work as well while you are using fosaprepitant. To keep from getting pregnant, use another form of birth control together with your pills during treatment and for one month after your last treatment. Other forms include condoms, diaphragms, and contraceptive foams or jellies.

Warnings While Using This Medicine

  • Make sure your doctor knows if you are pregnant or breastfeeding.
  • This medicine may cause serious allergic reactions. Tell your doctor or nurse right away if you have itching; hives; a rash; shortness of breath; trouble with breathing; trouble with swallowing; warmth or redness in your face, neck, arms, or upper chest; or any swelling of your hands, face, or mouth while you are receiving this medicine.
  • If you are also taking a blood thinner called warfarin (Coumadin®, Jantoven®), your doctor will need to check your blood after using 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
  • Blistering, peeling, or red skin rash.
  • Dry mouth, increased thirst, or muscle cramps.
  • Fast or slow heartbeat.
  • Fever, chills, cough, sore throat, and body aches.
  • Pain, itching, burning, swelling, or a lump under your skin where the needle is placed.
  • Severe stomach pain, nausea, or vomiting.
  • 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, heartburn, or stomach pain or upset.
  • Continuing ringing or buzzing or other unexplained noise in the ears.
  • Hair loss.
  • Headache or dizziness.
  • Hiccups.
  • Loss of appetite.
  • Mild skin rash.
  • Sores or white patches on your lips, mouth, or throat.
  • Tiredness or weakness.
  • Trouble with sleeping.

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

Version Info

  • Last Reviewed on 06/12/2013

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