It is very important that your doctor check your progress while you are using this medicine to make sure it is working properly and to check for unwanted effects.
This medicine may cause a serious type of allergic reaction called anaphylaxis. Anaphylaxis can be life-threatening and requires immediate medical attention. Call your doctor right away if you have itching; hives; rash; trouble with breathing; trouble with swallowing; or any swelling of your hands, face, or mouth while you are using this medicine.
Oral contraceptives (birth control pills) may not work as well while you are using aprepitant. To keep from getting pregnant, use another form of birth control together with your pills while you are using the medicine and for 1 month after your last dose. Other forms of birth control include condoms, diaphragms, or contraceptive foams or jellies.
If your symptoms do not improve or if they become worse, check with your doctor.
You should not use this medicine if you are also using astemizole (e.g., Hismanal®), cisapride (e.g., Propulsid®), pimozide (e.g., Orap®), or terfenadine (e.g., Seldane®). If you are taking any of these medicines, talk to your doctor before you start aprepitant.
Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines and herbal or vitamin supplements.