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Aprepitant Side Effects

For the Consumer

Applies to aprepitant: oral capsule, oral powder for suspension

Other dosage forms:

Along with its needed effects, aprepitant 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 immediately if any of the following side effects occur while taking aprepitant:

Less common
  • Black or tarry stools
  • chills
  • cough
  • fever
  • lower back or side pain
  • painful or difficult urination
  • pale skin
  • shortness of breath
  • sore throat
  • ulcers, sores, or white spots in the mouth
  • unusual bleeding or bruising
  • unusual tiredness or weakness
Incidence not known
  • Blistering, peeling, or loosening of the skin
  • confusion about identity, place, and time
  • diarrhea
  • itching or skin rash
  • joint or muscle pain
  • large, hive-like swelling on the face, eyelids, lips, tongue, throat, hands, legs, feet, or sex organs
  • redness of the skin
  • red, irritated eyes
  • red skin lesions, often with a purple center
  • slow or irregular heartbeat

Some side effects of aprepitant 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
  • Acid or sour stomach
  • belching
  • confusion
  • decreased urination
  • dizziness
  • dry mouth
  • fainting
  • heartburn
  • hiccups
  • increase in heart rate
  • indigestion
  • lack or loss of strength
  • lightheadedness
  • loss of appetite
  • nausea
  • rapid breathing
  • stomach discomfort upset or pain
  • sunken eyes
  • swelling or inflammation of the mouth
  • thirst
  • weight loss
  • wrinkled skin
Less common
  • Burning feeling in the chest or stomach
  • hot flashes
  • indigestion
  • pain or discomfort in the chest, upper stomach, or throat
  • tenderness in the stomach area

For Healthcare Professionals

Applies to aprepitant: intravenous emulsion, oral capsule, oral kit, oral powder for reconstitution


The most commonly reported side effects included fatigue, neutropenia, constipation, and pruritus.[Ref]


Very common (10% or more): Fatigue (up to 13%)
Common (1% to 10%): Asthenia, pyrexia
Uncommon (0.1% to 1%): Malaise
Rare (0.01% to 0.1%): Candidiasis, staphylococcal infection, tinnitus
Frequency not reported: Hypothermia, pain, postoperative infection, wound dehiscence[Ref]


Very common (10% or more): Neutropenia (up to 13%)
Common (1% to 10%): Anemia, hemoglobin decreased, white blood cell count decreased
Uncommon (0.1% to 1%): Febrile neutropenia
Rare (0.01% to 0.1%): Neutrophil count decreased
Frequency not reported: Blood albumin decreased, thrombocytopenia[Ref]


Common (1% to 10%): Abdominal pain, constipation, diarrhea, dyspepsia, eructation, flatulence, nausea, vomiting
Uncommon (0.1% to 1%): Dry mouth, gastroesophageal reflux disease
Rare (0.01% to 0.1%): Abdominal distention, duodenal ulcer perforation, feces hard, neutropenic colitis, stomatitis
Frequency not reported: Abdominal pain upper, bowel sounds abnormal, gastritis, oral candidiasis, stomach discomfort, subileus[Ref]


Common (1% to 10%): Bradycardia, flushing, hypertension, hypotension
Uncommon (0.1% to 1%): Hot flush, palpitations
Rare (0.01% to 0.1%): Cardiovascular disorder, chest discomfort, edema
Frequency not reported: Blood pressure decreased, edema peripheral, hematoma, operative hemorrhage[Ref]

Nervous system

Common (1% to 10%): Dizziness, headache
Uncommon (0.1% to 1%): Somnolence
Rare (0.01% to 0.1%): Cognitive disorder, dysgeusia, gait disturbance, lethargy
Frequency not reported: Dysarthria, hypoesthesia, peripheral neuropathy, sensory disturbance, syncope
Postmarketing reports: Ifosfamide-induced neurotoxicity[Ref]


Common (1% to 10%): ALT increased, AST increased
Uncommon (0.1% to 1%): Blood alkaline phosphatase increased
Frequency not reported: Blood bilirubin increased/bilirubin increased[Ref]


Common (1% to 10%): Cough, hiccups
Rare (0.01% to 0.1%): Oropharyngeal pain, postnasal drip, sneezing, throat irritation
Frequency not reported: Dyspnea, hypoxia, pharyngitis, respiratory depression, wheezing[Ref]


Common (1% to 10%): Decreased appetite, dehydration
Rare (0.01% to 0.1%): Blood sodium decreased, polydipsia, weight decreased
Frequency not reported: Blood glucose increased, blood potassium decreased/hypokalemia, hypovolemia[Ref]


Common (1% to 10%): Pruritus
Uncommon (0.1% to 1%): Acne, rash
Rare (0.01% to 0.1%): Hyperhidrosis, photosensitivity reaction, rash pruritic, seborrhea, skin lesion, Stevens-Johnson syndrome, toxic epidermal necrolysis
Frequency not reported: Alopecia, urticaria[Ref]


Common (1% to 10%): Insomnia
Uncommon (0.1% to 1%): Anxiety
Rare (0.01% to 0.1%): Abnormal behavior, agitation, behavior changes, disorientation, euphoric mood[Ref]


Common (1% to 10%): Urinary tract infection
Uncommon (0.1% to 1%): Dysuria
Rare (0.01% to 0.1%): Pollakiuria, proteinuria, red blood cells urine positive, urine output increased[Ref]


Rare (0.01% to 0.1%): Muscular weakness, muscle spasms
Frequency not reported: Musculoskeletal pain[Ref]


Rare (0.01% to 0.1%): Glucose urine present
Frequency not reported: Blood urea increased[Ref]


Frequency not reported: Anaphylactic reactions, angioedema, hypersensitivity reactions[Ref]


Rare (0.01% to 0.1%): Conjunctivitis
Frequency not reported: Miosis, visual acuity reduced[Ref]


1. "Product Information. Emend (aprepitant)." Merck & Company Inc, West Point, PA.

2. Cerner Multum, Inc. "Australian Product Information." O 0

3. Cerner Multum, Inc. "UK Summary of Product Characteristics." O 0

Some side effects of aprepitant may not be reported. Always consult your doctor or healthcare specialist for medical advice. You may also report side effects to the FDA.

Disclaimer: Every effort has been made to ensure that the information provided is accurate, up-to-date and complete, but no guarantee is made to that effect. In addition, the drug information contained herein may be time sensitive and should not be utilized as a reference resource beyond the date hereof. This material does not endorse drugs, diagnose patients, or recommend therapy. This information is a reference resource designed as supplement to, and not a substitute for, the expertise, skill , knowledge, and judgement of healthcare practitioners in patient care. The absence of a warning for a given drug or combination thereof in no way should be construed to indicate safety, effectiveness, or appropriateness for any given patient. does not assume any responsibility for any aspect of healthcare administered with the aid of materials provided. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the substances you are taking, check with your doctor, nurse, or pharmacist.