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Fosaprepitant Side Effects

Medically reviewed by Drugs.com. Last updated on Sep 20, 2024.

Applies to fosaprepitant: intravenous powder for solution.

Serious side effects of fosaprepitant

Along with its needed effects, fosaprepitant may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor or nurse immediately if any of the following side effects occur while taking fosaprepitant:

More common side effects

  • black, tarry stools
  • blurred vision
  • chest tightness
  • chills
  • confusion
  • cough
  • decreased urination
  • difficult or labored breathing
  • dizziness
  • dry mouth
  • fainting
  • fever
  • increase in heart rate
  • lightheadedness
  • lower back or side pain
  • nervousness
  • pain, swelling, or redness at the injection site
  • painful or difficult urination
  • pale skin
  • pounding in the ears
  • rapid breathing
  • slow or fast heartbeat
  • sore throat
  • sunken eyes
  • tenderness, swelling, warmth, or skin discoloration at the injection site
  • thirst
  • ulcers, sores, or white spots in the mouth
  • unusual bleeding or bruising
  • unusual tiredness or weakness
  • wrinkled skin

Less common side effects

  • hard lump at the injection site

Rare side effects

  • blood in the urine
  • changes in patterns and rhythms of speech
  • changes in skin color
  • chest pain or discomfort
  • fast, slow, irregular, pounding, or racing heartbeat or pulse
  • general feeling of discomfort or illness
  • headache
  • increased sweating
  • increased thirst
  • lightheadedness, dizziness, or fainting
  • loss of consciousness
  • muscle pain or cramps
  • nausea
  • pain, tenderness, or swelling of the foot or leg
  • seizures
  • slurred speech
  • swelling
  • swelling of the face, ankles, or hands
  • trouble with speaking
  • trouble breathing
  • vomiting

Incidence not known

  • diarrhea
  • difficulty with swallowing
  • hives or welts, itching
  • joint pain
  • large, hive-like swelling on the face, eyelids, lips, tongue, throat, hands, legs, feet, or genitals
  • puffiness or swelling of the eyelids or around the eyes, face, lips, or tongue
  • red skin lesions, often with a purple center
  • red, irritated eyes
  • redness of the skin

Other side effects of fosaprepitant

Some side effects of fosaprepitant may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects.

Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

More common side effects

  • belching
  • burning, crawling, itching, numbness, prickling, "pins and needles", or tingling feelings
  • continuing ringing or buzzing or other unexplained noise in ears
  • difficulty having a bowel movement
  • dizziness
  • feeling of indigestion
  • hair loss or thinning of the hair
  • hearing loss
  • hiccups
  • indigestion
  • lack or loss of strength
  • loss of appetite
  • pain in the chest below the breastbone
  • stomach discomfort, upset, or pain
  • swelling or inflammation of the mouth
  • weight loss

Less common side effects

  • feeling of warmth
  • pain or discomfort in chest, upper stomach, or throat
  • redness of the face, neck, arms, and occasionally, upper chest
  • sudden sweating
  • unusually warm skin

Rare side effects

  • abnormal dreams
  • blemishes on the skin
  • bumps on the skin
  • burning, dry, or itching eyes
  • change in taste
  • change in walking and balance
  • clumsiness or unsteadiness
  • confusion about identity, place, and time
  • difficulty with moving
  • discharge, excessive tearing
  • excess air or gas in the stomach
  • extreme thirst
  • false or unusual sense of well-being
  • flushed, dry skin
  • frequent urination
  • fruit-like breath odor
  • full feeling
  • heartburn
  • increased hunger
  • increased sensitivity of the skin to sunlight
  • increased urination
  • increased volume of pale, dilute urine
  • muscle ache, cramp, stiffness, or weakness
  • oily skin
  • passing gas
  • pimples
  • redness or other discoloration of the skin
  • redness, pain, or swelling of the eye, eyelid, or inner lining of the eyelid
  • severe constipation
  • severe sunburn
  • sleepiness
  • stomach distension
  • sweating
  • swollen joints
  • trouble performing routine tasks
  • trouble sleeping
  • unexplained weight loss
  • unusual drowsiness, dullness, or feeling of sluggishness
  • weight gain
  • white patches with diaper rash

For healthcare professionals

Applies to fosaprepitant: intravenous powder for injection, intravenous solution.

General adverse events

The most common side effects reported were fatigue, diarrhea, neutropenia, asthenia, anemia, peripheral neuropathy, leukopenia, dyspepsia, urinary tract infection, and pain in extremity.

Because fosaprepitant is converted to aprepitant, side effects associated with aprepitant may be expected to occur with this drug. The manufacturer product information for aprepitant should be consulted.[Ref]

Cardiovascular

Aprepitant:

Dermatologic

Aprepitant:

Gastrointestinal

Aprepitant:

Constipation and subileus occurred at higher doses of aprepitant.

Genitourinary

Aprepitant:

Hematologic

Aprepitant:

Hepatic

Aprepitant:

Hypersensitivity

Local

Infusion site reactions occurred in 2.2% of patients treated with this drug compared to 0.6% of patients treated with ondansetron and dexamethasone (standard therapy). These reactions included infusion-site pain, injection-site irritation, vessel puncture-site pain, and infusion-site thrombophlebitis.

Metabolic

Aprepitant:

Musculoskeletal

Aprepitant:

Rare (0.01% to 0.1%) Muscular weakness, muscle spasms

Nervous system

Aprepitant:

Ifosfamide-induced neurotoxicity has been reported after coadministration of this drug and ifosfamide.

Ocular

Aprepitant:

Other

Aprepitant:

Psychiatric

Aprepitant:

Respiratory

Aprepitant:

References

1. (2022) "Product Information. Emend for Injection (fosaprepitant)." Merck Sharp & Dohme LLC, SUPPL-21

2. (2022) "Product Information. Emend IV (fosaprepitant)." Merck Sharp & Dohme (Australia) Pty Ltd

3. (2022) "Product Information. Ivemend (fosaprepitant)." Merck Sharp & Dohme (UK) Ltd

Frequently asked questions

Further information

Fosaprepitant side effects can vary depending on the individual. Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Some side effects may not be reported. You may report them to the FDA.