Indications
Aprepitant is used together with other anti-sickness medicines (usually Dexamethasone and a medicine such as Ondansetron) to prevent nausea and vomiting caused by cancer chemotherapy, especially chemotherapy that is likely to cause strong sickness. It prevents sickness; it is not meant to treat vomiting that has already started.
How It Works
It blocks NK1 receptors in the brain. These receptors respond to a chemical called substance P, which is released during chemotherapy and triggers vomiting. Blocking them helps prevent both early and delayed sickness after treatment.
Dosage and Administration
Take exactly as prescribed by the cancer specialist. It is usually given as a short course of capsules over 3 days, with the first dose about 1 hour before chemotherapy on day 1 and further doses on the next mornings. Swallow the capsules whole with water, with or without food. Children: only as prescribed.
Interactions
- It can make hormonal contraceptives (pills, injections, implants) less effective during treatment and for 1 month afterwards; use an extra non-hormonal method such as condoms.
- It raises the level of Dexamethasone and Methylprednisolone, so the doctor usually adjusts their dose.
- It can lower the effect of Warfarin; blood clotting tests (INR) may be checked.
- Medicines such as Ketoconazole, Clarithromycin and Ritonavir can raise its level; Rifampicin, Carbamazepine and Phenytoin can lower it.
- It must not be taken with Pimozide.
Contraindications
- Allergy to Aprepitant or any ingredient of the capsule.
- Use with Pimozide, Terfenadine, Astemizole or Cisapride.
Side Effects
Common: tiredness, hiccups, loss of appetite, constipation, diarrhoea, indigestion and headache.
Get urgent medical help if you notice signs of an allergic reaction (swelling of the face or throat, difficulty breathing, widespread itchy rash), a severe blistering or peeling skin rash, or chest pain or a very fast heartbeat.
Pregnancy and Lactation
There is limited information on use in pregnancy, so it is used only if the doctor thinks it is clearly needed. Breastfeeding is not recommended during treatment. Because it weakens hormonal contraception, use extra non-hormonal protection.
Precautions and Warnings
Tell the doctor about any liver disease and all other medicines you take, as many medicines interact with it. Take the doses at the times you are told; missing the first dose before chemotherapy reduces protection. Do not drive if you feel tired or dizzy.
Overdose
Too much may cause drowsiness and headache. Contact a doctor or hospital; treatment is supportive.
Therapeutic Class
Antiemetic (anti-sickness medicine), NK1 receptor antagonist.
Storage
Store below 30°C in a dry place, away from light and out of the reach of children. Keep in the original pack.
Prepared by the Oshud Alo team from standard drug references. For information only; always follow your doctor's advice.