Aprepitant Pharmacology


About Aprepitant
Antiemetic belongs to a class of drugs called substance P antagonists (SPA).
Mechanism of Action of Aprepitant
Aprepitant is an antiemetic which acts as a substance P/neurokinin 1 (NK1) receptor antagonist. It also enhances antiemetic activity of 5HT3 antagonists and corticosteroid.
Pharmacokinets of Aprepitant
1.Absorption: Absorbed in the GI tract. Plasma concentrations peak after about 4 hr. Bioavailability: About 60-65%.
2.Distribution: Vd: About 70 L; crosses the blood-brain barrier
Plasma protein binding: >95%.
3.Metabolism: Undergoes extensive hepatic metabolism via oxidation by cytochrome P450 isoenzyme CYP3A4, the isoenzymes CYP1A2 and CYP2C19 mediate minor metabolic pathways.
4.Excretion: Primarily by metabolism.
Onset of Action for Aprepitant
Duration of Action for Aprepitant
Half Life of Aprepitant
About 9-13 hr.
Side Effects of Aprepitant
8.Abdominal pain
17.Elevated ALT and AST levels
19.Increased BUN.
20.Potentially Fatal: Hypersensitivity reactions, Steven-Johnsons syndrome.
Contra-indications of Aprepitant
Concomitant use with astemizole, cisapride, pimozide, terfenadine.
Special Precautions while taking Aprepitant
1.Moderate to severe hepatic impairment
2.Concurrent use with strong/moderate CYP3A4 inhibitors, inducers or substrates
3.Monitor INR closely for patients on warfarin
Pregnancy Related Information
Use with caution
Old Age Related Information
Use with caution
Breast Feeding Related Information
Not recommended
Children Related Information
Not recommended
Indications for Aprepitant
1.To prevention of chemotherapy-induced nausea and vomiting
2.Postoperative nausea and vomiting
Interactions for Aprepitant
1.Concurrent use with CYP3A4 inhibitors (e.g. clarithromycin, troleandomycin, diltiazem, verapamil, itraconazole, ketoconazole, nefazodone, ritonavir, nelfinavir) may lead to increased plasma levels of Aprepitant
2.Concurrent use with CYP3A4 inducers (e.g. carbamazepine, phenytoin, rifampicin, primidone, phenobarbital) may lead to reduced efficacy of Aprepitant
3.May decrease concentrations of CYP2C9 substrates e.g. phenytoin, tolbutamide, warfarin
4.May increase plasma levels of dexamethasone and methylprednisolone
5.May increase plasma levels of benzodiazepine (e.g. midazolam, diazepam, alprazolam)
6.Serum concentrations of colchicine may increase with Aprepitant
7.May increase toxicity of chemotherapy drug metabolised by CYP3A4 e.g. docetaxel, etoposide, ifosfamide, imatinib, paclitaxel, vincristine, vinblastin
8.May increase levels of ergot derivatives resulting in ergotism
9.May reduce efficacy of oral contraceptives, use additional methods of contraception during treatment and for at least 1 mth following the last dose of Aprepitant.
10.Potentially Fatal: May result in increased serum levels of astemizole, cisapride, pimozide and terfenadine which can lead to life-threatening torsade de pointes arrhythmias.
Typical Dosage for Aprepitant
Prophylaxis of chemotherapy-induced nausea and vomiting
Adult: To be given for 3 days as part of a regimen containing a corticosteroid and a 5HT3 antagonist. Day 1: 125 mg (1 hr before chemotherapy); days 2 and 3: 80 mg once daily.

Prophylaxis of postoperative nausea and vomiting
Adult: 40 mg within 3 hr prior to induction of anaesthesia.
Schedule of Aprepitant
Storage Requirements for Aprepitant
Oral: Store at room temperature 20-25?C (68-77?F).
Effects of Missed Dosage of Aprepitant
Effects of Overdose of Aprepitant

Home Delivery for Aprepitant in Your City

Medicine India is just a publishing medium for medicine related information and does not provide services or sales of medicines including aprepitant.

However, we do publish a comprehensive directory of Pharmacies, Chemists and Druggists in cities all over India. You can use this directory to find the medicine stores in your city (or area) that provide home delivery services for aprepitant and other medicines and health products. Home delivery services for aprepitant may be free or they may cost you depending on the pharmacy and the minimum order requirements. It would be best to get this clarified while placing the order.

Please be aware that you should take aprepitant only if a doctor has recommended or prescribed it. Some or all pharmacies who provide a home delivery service for medicines might insist on a prescription for aprepitant before they complete the sale. You can get this information while placing the order for aprepitant with the pharmacy.

Aprepitant is a generic medicine name and there are several brands available for it. Some of the brands for aprepitant might be better known than aprepitant itself. If the pharmacy that's willing to deliver medicines to your home doesn't have aprepitant in stock, you can ask for one of the branded alternatives for aprepitant.