Prescription medication · NK1 Receptor Antagonist (Antiemetic)
aprepitant
Also sold as Emend. Aprepitant is used to prevent nausea and vomiting caused by chemotherapy.
Data updated 2026-05-15
- 17,740
- FDA reportsModerately reported
- 22
- InteractionsSeveral interactions
- 44% less
- Generic vs brandReal savings
- 1
- Recall record
What the data shows
aprepitant (Emend) is a prescription NK1 Receptor Antagonist (Antiemetic), reported at a middle-of-the-pack volume (17,740 FDA reports), with a lower-cost generic available (44% less than brand).
Reporting volume reflects how widely a drug is used and studied, not how dangerous it is, a FAERS report documents a temporal association, never proof of cause.
aprepitant (Emend) is a prescription NK1 Receptor Antagonist (Antiemetic). Aprepitant is used to prevent nausea and vomiting caused by chemotherapy.
Aprepitant (Emend) is a medicine that helps prevent nausea and vomiting. It belongs to a class of drugs called NK1 receptor antagonists.
Verify with FDA → · CMS NADAC pricing →
Drug Pricing (NADAC)
Brand Price
$325.22/unit
Generic Price
$182.16/unit
Generic Savings
44%
Generic Available
Yes (3 manufacturers)
Pricing data from NADAC (CMS), effective December 18, 2024. Compare all drug costs →
What it does
Aprepitant is used to prevent nausea and vomiting caused by chemotherapy.
Common side effects
Tiredness, Diarrhea, Weakness
Key warnings
Aprepitant can interact with other medicines.
The sections below are summarized in plain English from aprepitant's FDA-approved prescribing information. They describe what the official label says, and are not personal medical advice.
How It Works
Aprepitant blocks a substance in your body called substance P. Substance P can trigger nausea and vomiting. By blocking it, aprepitant helps reduce these side effects.
Side Effects (from patient reports)
Based on 17,740 FDA adverse event reports.
Most-reported reactions
Adverse reactions in FAERS for aprepitant, by number of reports
- Nausea
Nausea
2,145 reports
- Fatigue
Fatigue
1,769 reports
- Pyrexia
Pyrexia
1,589 reports
- Diarrhoea
Diarrhoea
1,542 reports
- Dyspnoea
Dyspnoea
1,508 reports
- Vomiting
Vomiting
1,474 reports
- Alopecia
Alopecia
1,274 reports
- Rash
Rash
1,210 reports
- Hypersensitivity
Hypersensitivity
1,133 reports
- Febrile Neutropenia
Febrile Neutropenia
1,043 reports
What this shows Bars show how often each reaction was reported, not how likely it is to happen, a report records a temporal association, never proof that the drug caused it.
Reports over time
Adverse-event reports filed for aprepitant each year to the FDA Adverse Event Reporting System (FAERS).
Year-to-year volume tracks usage, prescribing, and scrutiny, not a change in per-patient risk. Source: FDA FAERS.
Where aprepitant sits
aprepitant has more FDA adverse-event reports than 52% of the drugs FAERS tracks. A high position reflects how widely a drug is used and watched, not how dangerous it is.
Percentile across all drugs PlainMeds tracks by FAERS report volume. The dot is aprepitant; the line is the median (50th percentile).
FDA Adverse Event Report Analysis
Detailed analysis of 17,740 reports from the FDA Adverse Event Reporting System (FAERS). Reports span 2004–2025.
Total Reports
17,740
Reports Mentioning Death
2,942
16.6% of reports — not proof of cause
Hospitalization Reports
9,758
Top Indication
Product Used For Unknown Indication
Gender Distribution
Age Distribution
Most Reported Adverse Reactions (FAERS)
| # | Reaction | Reports |
|---|---|---|
| 1 | NAUSEA | 2,145 |
| 2 | FATIGUE | 1,769 |
| 3 | PYREXIA | 1,589 |
| 4 | DIARRHOEA | 1,542 |
| 5 | DYSPNOEA | 1,508 |
| 6 | VOMITING | 1,474 |
| 8 | ALOPECIA | 1,274 |
| 9 | RASH | 1,210 |
| 10 | HYPERSENSITIVITY | 1,133 |
| 11 | FEBRILE NEUTROPENIA | 1,043 |
| 12 | DECREASED APPETITE | 1,038 |
| 13 | PRURITUS | 1,020 |
| 14 | STOMATITIS | 992 |
| 15 | INFUSION RELATED REACTION | 972 |
| 16 | PAIN | 955 |
Reactions in Death Reports
Reactions in Hospitalization Reports
Source: FDA FAERS (Adverse Event Reporting System) Reports are voluntary and do not establish causation
Serious Warnings
Aprepitant can interact with other medicines. It can affect how well warfarin (a blood thinner) and hormonal birth control work. If you take warfarin, your doctor will check your blood. If you use hormonal birth control, use a backup method while taking aprepitant and for 28 days after your last dose.
Known Drug Interactions
Table 10: Effects of Aprepitant on the Pharmacokinetics of Other Drugs CYP3A4 Substrates Pimozide Clinical Impact Increased pimozide exposure Intervention Aprepitant is contraindicated [see Contraindications ( 4 )] . Table 10: Effects of Aprepitant on the Pharmacokinetics of Other Drugs CYP3A4 Substrates Pimozide Clinical Impact Increased pimozide exposure Intervention Aprepitant is contraindicated [see Contraindications ( 4 )] .
Mechanism: Aprepitant stops the body from breaking down pimozide, which can cause pimozide to build up to dangerous levels in the blood.
Benzodiazepines Clinical Impact Increased exposure to midazolam or other benzodiazepines metabolized via CYP3A4 (alprazolam, triazolam) may increase the risk of adverse reactions [see Clinical Pharmacology ( 12.3 )]. Benzodiazepines Clinical Impact Increased exposure to midazolam or other benzodiazepines metabolized via CYP3A4 (alprazolam, triazolam) may increase the risk of adverse reactions [see Clinical Pharmacology ( 12.3 )].
Mechanism: Aprepitant slows down how fast your body processes alprazolam, which causes the drug to build up in your blood. This can make you feel much more sleepy or dizzy than usual.
Intervention Avoid concomitant use of aprepitant Examples Moderate inhibitor: diltiazem Strong inhibitors: ketoconazole, itraconazole, nefazodone, troleandomycin, clarithromycin, ritonavir, nelfinavir Strong CYP3A4 Inducers Clinical Impact Substantially decreased exposure of aprepitant in patients chronically taking a strong CYP3A4 inducer may decrease the efficacy of aprepitant [see Clinical Pharmacology ( 12.3 )] . Intervention Avoid concomitant use of aprepitant Examples Moderate inhibitor: diltiazem Strong inhibitors: ketoconazole, itraconazole, nefazodone, troleandomycin,...
Mechanism: Diltiazem slows down the body's ability to process aprepitant, which can increase the amount of aprepitant in your blood.
Single 40 mg dose of aprepitant No dosage adjustment of oral dexamethasone needed Methylprednisolone Clinical Impact Increased methylprednisolone exposure [see Clinical Pharmacology ( 12.3 )]. Intervention 3-day aprepitant regimen Reduce the dose of intravenous methylprednisolone by approximately 25% Reduce the dose of oral methylprednisolone by approximately 50% Single 40 mg dose of aprepitant No dosage adjustment of methylprednisolone needed Chemotherapeutic agents that are metabolized by CYP3A4 Clinical Impact Increased exposure of the chemotherapeutic agent may increase the risk of...
Mechanism: Aprepitant prevents the body from breaking down methylprednisolone, which leads to higher levels of the steroid in your system.
Intervention Avoid concomitant use of aprepitant Examples Moderate inhibitor: diltiazem Strong inhibitors: ketoconazole, itraconazole, nefazodone, troleandomycin, clarithromycin, ritonavir, nelfinavir Strong CYP3A4 Inducers Clinical Impact Substantially decreased exposure of aprepitant in patients chronically taking a strong CYP3A4 inducer may decrease the efficacy of aprepitant [see Clinical Pharmacology ( 12.3 )] . Intervention Avoid concomitant use of aprepitant Examples Moderate inhibitor: diltiazem Strong inhibitors: ketoconazole, itraconazole, nefazodone, troleandomycin,...
Mechanism: Ketoconazole strongly blocks the enzymes that clear aprepitant from your body, causing drug levels to rise.
This is a plain-language summary of FDA-label interaction records and does not provide individual medication-combination directions.
Common Questions
Can I take aprepitant with food?
What should I do if I experience side effects?
Can I take aprepitant if I am allergic to any of its ingredients?
Can aprepitant be used to treat nausea that has already started?
How long can I take aprepitant?
What dose of aprepitant should I take for chemotherapy?
What dose of aprepitant should I take for post-operative nausea?
Can children take aprepitant?
What if I am taking other medications?
Are there any reasons I should not take aprepitant?
What are the common side effects of aprepitant?
Does aprepitant interact with other medications?
What drug class is aprepitant?
Is there a generic version of aprepitant?
What pregnancy or breastfeeding source fields are listed for aprepitant?
Has aprepitant been recalled?
Active Recalls
Presence of particulate matter: potential presence of metal particulates in the product.
Merck Sharp & Dohme LLC
Related Medications in NK1 Receptor Antagonist (Antiemetic)
Other drugs grouped near aprepitant - same-class peers and common alternatives.
alosetron
Lotronex
Alosetron (Lotronex) is a medicine for women with severe diarrhea-predominant irritable bowel syndrome (IBS).
Compare with aprepitant →
bisacodyl
Dulcolax
Bisacodyl is a medicine that helps you have a bowel movement.
Compare with aprepitant →
bismuth subsalicylate
Pepto-Bismol
Bismuth subsalicylate (Pepto-Bismol) is a medicine that can treat diarrhea and upset stomach.
Compare with aprepitant →
cimetidine
Tagamet
Cimetidine (Tagamet) reduces stomach acid.
Compare with aprepitant →
dexlansoprazole
Dexilant
Dexlansoprazole (Dexilant) is a medicine that lowers stomach acid.
Compare with aprepitant →
Compare beyond drug class
Nationwide peers by FAERS volume & death-report share
Two PlainMeds-derived comparison paths for aprepitant: nearest FDA FAERS report volume and nearest death-report share among drugs with at least 1,000 logged reports, excluding same-class neighbors listed above. Counts reflect reporting volume, not proven individual harm.
Similar FAERS report volume
Nearest drugs by total FAERS reports. This record: 17,740.
Similar death-report share
Nearest drugs by FAERS death-report share. This record: 16.58%.
- haloperidol Δ 0.00 pts · 23,495 reports · Typical Antipsychotic 16.58%death share
- glucagon Δ 0.00 pts · 3,944 reports · Glucagon (Hypoglycemia Rescue) 16.58%death share
- piroxicam Δ 0.00 pts · 6,176 reports · Nonsteroidal Anti-Inflammatory Drug (NSAID) 16.58%death share
- octreotide Δ 0.05 pts · 5,230 reports · Somatostatin Analog 16.63%death share
Medication Guides
Understanding Drug Interactions
How CYP450 enzymes, inhibitors, and inducers affect your medications
Generic vs Brand Name Drugs
FDA requirements, cost savings, and when the difference matters
Narrow Therapeutic Index Drugs
FDA bioequivalence and label-record context for narrow therapeutic index medicines
Common Drug Interactions
Dangerous medication combinations and how to protect yourself
Save on aprepitant
Compare prices and find discounts at pharmacies near you. Free coupons can save up to 80% on prescriptions.
Disclosure: This link may earn us a commission at no extra cost to you. See our terms.
What the FDA Data Shows for aprepitant
The FDA label for aprepitant (sold under brand names such as Emend) classifies it as a prescription-only medication in the NK1 Receptor Antagonist (Antiemetic) class. Aprepitant is used to prevent nausea and vomiting caused by chemotherapy. Official labeling lists 17 commonly reported side effects, including Tiredness, Diarrhea, Weakness.
Post-market surveillance from the FDA Adverse Event Reporting System (FAERS) captures real-world experience. For this drug, FAERS contains 17,740 voluntary reports. The database also lists 22 documented drug interactions derived from FDA labeling, with the top-flagged interaction rated major severity. NADAC pricing from CMS shows a generic unit cost of $182.16 versus $325.22 for the brand - a 44% generic savings.
Report counts do not establish causation, a FAERS entry documents a temporal association, not proof that the drug produced the outcome. Widely prescribed medications naturally accumulate more reports than niche therapies, so raw totals must be interpreted alongside total exposure. Shortage status, recall history (currently 1 recall record on file), and patent information are separate source-record fields. This page is a public FDA/CMS registry and does not provide medical, treatment, substitution, or medication-change directions.
Data Sources
Drug labeling: FDA Drug Labels (SPL/DailyMed). Adverse events: FDA Adverse Event Reporting System (FAERS). Pricing: CMS National Average Drug Acquisition Cost (NADAC).
FAERS reports are voluntary and do not establish causation. Drug interactions are derived from FDA labeling and clinical references. This registry does not provide medication decisions.
Last updated: October 16, 2025
PlainMeds is rendered directly from FDA openFDA/FAERS extracts, DailyMed labels, and CMS drug-pricing files, no number is typed in by an editor. FAERS counts, recalls, shortages, and price figures on this page are queried live from those federal extracts. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of 2026-05-15. Primary sources: openFDA / FAERS, DailyMed and CMS Part B ASP.
Read our methodology - how this data is sourced, computed, and verified.
Data currency: FDA FAERS adverse-event reports through 2025, CMS NADAC acquisition-cost pricing effective December 2024, compiled from the source snapshot dated . See our methodology for per-source dates and refresh cadence. Spot a figure that looks wrong? Report a data issue.
All federal data sources used on this page
- FDA Orange Book - approved drug products with therapeutic equivalence. accessdata.fda.gov/cder/ob
- FDA DailyMed - NIH-hosted drug labeling for FDA-approved meds. dailymed.nlm.nih.gov
- FDA Adverse Event Reporting System (FAERS) - post-marketing safety surveillance. fda.gov/drugs/faers
- NLM RxNorm - standardized clinical drug nomenclature. nlm.nih.gov/research/umls/rxnorm
- CMS Medicare Part B Drug Average Sales Price Files - federal drug pricing data. cms.gov/medicare/part-b-drugs/asp
- FDA Drug Shortages Database - current and resolved drug shortage tracking. accessdata.fda.gov/drugshortages