Aprepitant (Oral)

Aprepitant is prescribed for cancer or surgery patients to alleviate vomiting after chemotherapy medication.


Aprepitant helps to alleviate vomiting when it occurs as a result of chemotherapy medications in adults and children (at least 12 years old) within 24 hours of receiving therapy. It is also prescribed to provide relief for vomiting when it occurs as a result of surgery in adults. Aprepitant is given ahead of time, prior to treatment. Aprepitant works by obstructing neurokinin, a nausea and vomiting-inducing substance that occurs naturally in the brain. This medication comes in capsule and powder for suspension form.

Aprepitant is produced in oral suspension and capsule form. Once taken, aprepitant becomes active in the nervous system and it blocks the chemical that triggers vomiting. Aprepitant is manufactured under the US brand name of Emend and is only accessible with a doctor's prescription. A physician will ensure that there will be a lower chance of side effects from potential interactions.

Prior to Use

A patient should weigh the positive and negative aspects of any medication prior to taking it. The patient must work together with the doctor to determine if aprepitant is right for them. Refer to the summary on Warnings and Interactions for dangerous interactions that can occur when this medication is combined with other prescriptions.


Ensure the doctor is aware of any type of uncommon or allergic reactions to the medicine, including but not limited to skin rash, hives, or additional skin irregularities. Do not continue to use this medicine if an allergic reaction takes place; seek medical advice prior to continuing use.

The doctor must also be informed of additional allergies, such as food, dyes, preservatives, or animals. Read the directions on the medication label thoroughly for any products purchased over the counter, as these ingredients can also contribute to negative interactions with aprepitant.

Condition(s) treated?

  • Nausea
  • Vomiting

Type of medicine

  • Antiemetic

Side Effects

Medications tend to have unwanted side effects that occur along with the positive benefits. Not all side effects will happen, however, they may require medical care if they do take place.

Consult with your physician right away if these side effects take place:

Less common side effects - medical attention required:

  • Back pain
  • Bleeding (unusual)
  • Breath shortness
  • Bruising (unusual)
  • Chills
  • Cough
  • Fever
  • Mouth sores, ulcers, or white spots
  • Side pain
  • Skin paleness
  • Stool irregularity (tarry or black)
  • Throat soreness
  • Weakness/tiredness (unusual)

Side effects (Incidence not known) - medical attention required:

  • Skin peeling, loosening, or blistering
  • Mental confusion (time, place, identity)
  • Diarrhea
  • Skin rash or itching
  • Muscle pain
  • Joint pain
  • Skin redness/lesions (red with purple middle)
  • Eye irritation (redness)
  • Heartbeat irregularity (slowness)
  • Swelling of the tongue, eyelids, throat, face, lips, legs, hands, feet, genitals

Occasionally, aprepitant causes side effects that do not need medical care. As the body regulates more to the medication, the side effects may begin to subside over the remaining treatment course. A doctor can give you more information regarding how to reduce or prevent many of these side effects.

Consult your physician if there are any questions regarding the following side effects, or if any of these persist or are troublesome.

More common side effects - medical attention not required

  • Appetite loss
  • Breathing quickness
  • Confusion
  • Dizziness
  • Eyes recessed
  • Fainting
  • Heart rate increase
  • Heartburn
  • Hiccups
  • Indigestion
  • Lightheadedness
  • Mouth dryness
  • Mouth inflammation or swelling
  • Nausea
  • Skin wrinkles
  • Stomach acidity or sourness
  • Stomach pain or discomfort
  • Strength loss/lack
  • Thirst
  • Urination decrease
  • Weight loss

Less common side effects - medical attention not required

  • Indigestion
  • Chest discomfort or pain
  • Stomach (upper) discomfort or pain
  • Throat discomfort or pain
  • Hot flashes
  • Chest burning sensation
  • Stomach burning sensation
  • Stomach tenderness

There can occasionally be additional side effects not included here that can occur for certain individuals. If any additional side effects take place, be sure to consult your doctor regarding how to treat them.

Your doctor should be contacted with all medical questions regarding side effects. The FDA also allows side effects to be reported at 1-800-FDA-1088.


This medication should only be taken according to the directions from your physician in order to help your unique circumstance in the most optimal way. Never take aprepitant more frequently than prescribed, for a longer duration than prescribed, or more than what was prescribed by the doctor.

There is an informational leaflet included with this medication. The instructions should be followed and read carefully. Consult your physician if you have any questions or issues.

This medication is not intended to be for long-term use. When treating patients with chemotherapy, only three doses total will likely be needed. When treating patients before surgery, they will likely only receive one dose.

Aprepitant can sometimes be prescribed simultaneously with other medications to reduce the chance of vomiting due to chemotherapy. Cautiously abide by the directions of your doctor in regards to taking the medication.

This medication may be taken with or without food.

Be sure to swallow the entire capsule at once. Do not chew, break, or crush the capsule.

For oral suspension use, each dose will come from a dispenser that is prefilled with your oral dose. Consult your physician immediately if the patient cannot take a dose for any reason. Dispose of the oral dose cap and dispenser following every use.

Individuals who already experience vomiting and nausea should not begin taking aprepitant, as these symptoms will only be intensified. Speak with your physician regarding how to proceed with your prescriptions.

Different individuals may receive distinct prescriptions as the medication varies, depending on patient and illness characteristics. Only take this medication according to the physician's directions or the instructions on the label. The information below gives only average doses of aprepitant. Do not change your dose unless your physician instructs you to adjust it.

The strength of the medication determines the total quantity of aprepitant needed. Additionally, the medical problem and the total dose count each day, how spaced out the doses are, and the time it takes to take the medication will determine how the medication is prescribed. The capsules are available in two strengths, but the doctor will decide which strength is right for you. The physician may decide to prescribe both strengths intending for them to be taken at specific times. It is important to ensure you are taking the right strength that the doctor intended at the right time.

The initial dose of aprepitant is typically taken an hour prior to chemotherapy treatment, or three hours prior to surgery.

Capsule oral dosage form:

To counteract vomiting and nausea triggered by chemotherapy:

  • Adult dose: Typically 125 milligrams (mg) one hour prior to day one of chemotherapy. Afterward, 80 mg should be taken one time in the morning on days two and three.
  • Child dose: Children younger than 12 who can safely take a capsule can take 125 milligrams of aprepitant up to one hour prior to day one of chemotherapy (they must weigh more than 30 kg). Afterward, 80 mg can be taken once in the mornings on days two and three. Children younger than 12 who weigh less than 30 kg should consult their doctor for dosage information.

To counteract vomiting and nausea triggered by surgery:

  • Adult dose: Typically 40 milligrams (mg) three hours prior to surgery
  • Child dose: The pediatrician must determine dosage

Powder for suspension oral dosage form:

To counteract vomiting and nausea triggered by chemotherapy:

  • Adult dose: Typically 3 milligrams (mg) for each kilogram (kg) of weight. The highest dose that should be taken is 125 mg up to one hour prior to day one of chemotherapy. After, take 2 mg per kg of body weight. The highest dose that should be taken is up to 80 mg one time during the morning on chemotherapy days two and three.
  • Child dose: the pediatrician must determine dosage.

Missed Dose

Never take a double dose of this medication. If a dose is missed, take the dose immediately after noticing the dose had been missed. However, the dose must be skipped if it is closer to the scheduled next dose.


Urgent medical care should be obtained. The Poison Help phone line is 1-800-222-1222.


Some prescriptions should not be combined, but in certain cases, two medications can be used at the same time despite the chances that an interaction could take place. Under these circumstances, the physician could adjust the dose or take additional precautions to protect the patient.

It is imperative that the physician is aware of all medication that a patient is taking. The medications listed below have significant interactions. The following list has been chosen due to the likely significance of the medications but is not completely all-inclusive.

Not recommended to combine

  • Pimozide - severe interaction
  • Lomitapide
  • Flibanserin

Not recommended to combine (In some circumstances it may not be optional)

  • Warfarin
  • Voriconazole
  • Verapamil
  • Venetoclax
  • Tolvaptan
  • Telithromycin
  • Telaprevir
  • Tacrolimus
  • St John's Wort
  • Sonidegib
  • Simeprevir
  • Saquinavir
  • Ritonavir
  • Rifampin
  • Ranolazine
  • Posaconazole
  • Piperaquine
  • Phenytoin
  • Oxycodone
  • Olaparib
  • Nelfinavir
  • Nefazodone
  • Naloxegol
  • Mitotane
  • Lurasidone
  • Lumacaftor
  • Lopinavir
  • Ketoconazole
  • Ivacaftor
  • Ivabradine
  • Itraconazole
  • Indinavir
  • Imatinib
  • Idelalisib
  • Ibrutinib
  • Hydrocodone
  • Fosphenytoin
  • Fluconazole
  • Fentanyl
  • Erythromycin
  • Eplerenone
  • Enzalutamide
  • Dronedarone
  • Doxorubicin Hydrochloride Liposome
  • Doxorubicin
  • Domperidone
  • Docetaxel
  • Diltiazem
  • Dasatinib
  • Conivaptan
  • Colchicine
  • Cobimetinib
  • Cobicistat
  • Clozapine
  • Clarithromycin
  • Cilostazol
  • Ceritinib
  • Carbamazepine
  • Brexpiprazole
  • Bosutinib
  • Boceprevir
  • Atazanavir

It may be dangerous to combine aprepitant with any of the following medications. There can be an increase of severe side effects if aprepitant is combined with another prescription. It may be the case that the incorporation of both medications is the most optimal form of treatment. Your physician may alter the dosage frequency or amount of either medication if needed.

  • Suvorexant
  • Sirolimus
  • Quetiapine
  • Norgestrel
  • Norgestimate
  • Norethindrone
  • Norelgestromin
  • Midazolam
  • Methylprednisolone
  • Mestranol
  • Medroxyprogesterone Acetate
  • Levonorgestrel
  • Etonogestrel
  • Ethynodiol Diacetate
  • Ethinyl Estradiol
  • Estradiol Valerate
  • Estradiol Cypionate
  • Drospirenone
  • Dienogest
  • Dexamethasone
  • Desogestrel

Other Interactions

Some medications should not be taken at mealtimes or when eating particular kinds of food due to potential interactions that can occur. In this case, grapefruit juice should be avoided. The use of tobacco or alcohol can also trigger interactions. This information is not necessarily all-inclusive, as there could be additional interactions with foods or beverages that are not currently known.


Ensure a doctor monitors the progress of the patient while taking this medication, as they need to be sure it is working the way it should be. The physician must also look for undesirable side effects.

If patients are already taking pimozide (Orap®), they should not also take aprepitant. The combination could cause even more severe and unwarranted side effects.

A patient with liver disease should disclose all information about their illness to their physician to determine whether or not it is safe for them to take aprepitant.

Severe allergic reactions can occur while taking this medication, and anaphylaxis is one of them. Urgent medical care is required for anaphylaxis as it is sometimes a life-threatening illness. Contact your physician immediately if the patient experiences rashes, hives, itching, difficulty breathing, trouble swallowing, or swelling of the hands, mouth, or face while taking this medication.

Aprepitant may cause complications when combined with birth control pills. Another form of birth control should be used during the time the medication is required, and for one month after the final dose of aprepitant. Additional types of birth control are diaphragms, condoms, or contraceptive jellies or foams. No other prescription medication should be taken unless pre-approved by your physician. The physician should also confirm that it is OK to take medications that are available over the counter such as Tylenol, vitamins, or herbal supplements prior to taking them.

This medication should not be shared with anyone. Aprepitant is not intended to treat overall nausea that is not related to surgery or chemotherapy.

Specific demographic use


There have not been correlating studies in regards to prescribing aprepitant to children. It is not currently known whether or not the medication can prevent vomiting and nausea after surgery or cancer medicines, and it is not understood if the medicine is efficient and safe for children.


There have not been any current studies that have revealed issues exclusive to the geriatric population that would inhibit the efficacy of aprepitant for elderly.


Do not take aprepitant while breastfeeding. There have not been correlating studies in regards to prescribing aprepitant to women who are breastfeeding, so it should not be attempted. Potential risk to the infant has not been determined. Women should consider the positive and negative aspects of taking this prescription while breastfeeding.


Do not store medication in an area where children can easily get to it. Discard any medication that is expired or medication that is no longer necessary. Consult your doctor to understand how to properly throw away unused medication.

Aprepitant should be stored at a moderate room temperature in a sealed container. It should be kept away from direct light, dampness, freezing temperatures, and excessive warmth.

The oral liquid aprepitant (in the oral dosing unit) must be kept in the refrigerator for a maximum of 72 hours prior to use.

Aprepitant can be stored at room temperature for a maximum of three hours.


Aprepitant is used in a treatment plan with other medicines to reduce vomiting and nausea; it can be taken up to 24 hours after chemotherapy. It can also be used after surgery as an anti-nausea medication for patients who are experiencing vomiting as a side effect. This medication is not for treating vomiting conditions that are preexisting. Different people will likely receive different prescriptions, as their particular medical situation will typically vary from the next person. Specific illness and patient aspects will determine the need for varied prescriptions. Never adjust your dose or medication amount without having your doctor's approval.

Last Reviewed:
December 23, 2017
Last Updated:
April 04, 2018
Content Source: