Aprepitant (aprepitant)
Multiple manufacturers (generic); brand: Emend by Merck · NK1 Receptor Antagonist / Antiemetic
What is Aprepitant? Aprepitant (brand: Emend) is an NK1 receptor antagonist used as part of combination antiemetic therapy to prevent acute and delayed nausea and vomiting associated with highly emetogenic chemotherapy (HEC) and moderately emetogenic chemotherapy (MEC).
About Aprepitant
| Brand Name | Aprepitant |
| Generic / INN | aprepitant |
| Drug Class | NK1 Receptor Antagonist / Antiemetic |
| Manufacturer | Multiple manufacturers (generic); brand: Emend by Merck |
| Administration | Oral capsule |
| FDA Approval | 2003 |
FDA-Approved Uses for Aprepitant
Indications are based on FDA approval. Your healthcare provider determines appropriate use based on your specific diagnosis, stage, biomarker status, and overall clinical picture.
- Prevention of acute and delayed nausea and vomiting associated with highly emetogenic cancer chemotherapy (HEC)
- Prevention of nausea and vomiting associated with moderately emetogenic chemotherapy (MEC)
- Prevention of postoperative nausea and vomiting (PONV) — adult patients
How Does Aprepitant Work?
Aprepitant is a selective high-affinity antagonist of the NK1 (neurokinin 1) receptor — the primary receptor for substance P in the brain's vomiting center. By blocking substance P from binding NK1 receptors in the central and peripheral nervous system, aprepitant prevents chemotherapy-induced nausea and vomiting (CINV), particularly the delayed phase (24–120 hours post-chemotherapy).
Dosage & Administration
Standard 3-day regimen for HEC: Day 1: 125 mg orally 1 hour before chemotherapy. Days 2 and 3: 80 mg orally once daily in the morning. Used in combination with a 5-HT3 antagonist (e.g., ondansetron) and dexamethasone per CINV guidelines.
Dosing is individualized by the prescribing clinician. Never adjust your dose without consulting your healthcare provider. This information is educational only and does not replace the official prescribing information.
Warnings, Precautions & Side Effects
General Warning
CYP3A4 drug interactions — aprepitant is a moderate inhibitor of CYP3A4 and a CYP2C9 inducer. Can increase levels of CYP3A4 substrates (including dexamethasone — adjust dose). Can reduce efficacy of hormonal contraceptives. Chronic continuous use not recommended.
- CYP3A4 drug interactions (clinically significant)
- Hormonal contraceptive failure
- Hypersensitivity reactions (rare)
Common Side Effects
- Fatigue
- Nausea
- Hiccups
- Constipation
- Diarrhea
- Decreased appetite
- Headache
This is not a complete list. Always report new or worsening symptoms to your healthcare provider promptly.
Storage & Handling
Store at room temperature 20°C to 25°C (68°F to 77°F).
BiologicHealthPlus provides temperature-monitored cold-chain specialty delivery for medications requiring refrigeration. Never use a medication if its storage conditions have been compromised.
Insurance Coverage, Prior Authorization & Patient Assistance
🛡️ Commercial Insurance
Aprepitant is covered by most major commercial insurance plans when medically necessary and prior authorized. Coverage tier and cost-sharing vary by plan.
✅ Prior Authorization
Prior authorization is required by virtually all insurance plans for Aprepitant. BiologicHealthPlus handles the complete prior authorization process at no cost to patients or providers.
🏥 Medicare Coverage
Medicare Part D covers this oral specialty medication. Medicaid coverage varies by state.
🆓 Patient Assistance
Manufacturer patient assistance programs may be available for eligible uninsured or underinsured patients. Contact BiologicHealthPlus for a confidential eligibility review.
Prior Authorization Patient Assistance Insurance & Savings Medication Costs
Frequently Asked Questions — Aprepitant
Aprepitant is an NK1 receptor antagonist antiemetic used to prevent chemotherapy-induced nausea and vomiting (CINV), particularly the delayed phase (beyond 24 hours after chemotherapy). It is used as part of a 3-drug antiemetic regimen with a 5-HT3 antagonist and dexamethasone.
Aprepitant blocks the NK1 receptor in the brain's vomiting center, preventing substance P from triggering the nausea and vomiting reflex — particularly the delayed CINV that occurs 24–120 hours after chemotherapy.
Yes. Generic aprepitant capsules (125 mg and 80 mg) are widely available. The original brand is Emend (Merck).
Yes. Aprepitant is a moderate CYP3A4 inhibitor and CYP2C9 inducer. It increases levels of dexamethasone (dose reduction needed) and other CYP3A4 substrates. It can reduce the effectiveness of hormonal contraceptives.
Related Medications & Conditions
Related Medications
Ondansetron (Zofran) · Fosaprepitant (Emend IV) · Dexamethasone · Rolapitant (Varubi) · Netupitant/palonosetron (Akynzeo)
Related Conditions
Chemotherapy-induced nausea and vomiting (CINV) · Highly emetogenic chemotherapy · Postoperative nausea and vomiting