PlainMeds provides educational information only. This is not medical advice. Always consult your doctor or pharmacist.

aprepitant vs ketoconazole

Side-by-side comparison of aprepitant and ketoconazole. Data from FDA drug databases (Orange Book, NDC Directory, recalls, shortages) covering 20,000+ approved drugs, plus CMS pricing; see our methodology.

moderate Known Drug Interaction

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,...

Recommendation: You should avoid using these two medications together.

Drug Class
aprepitant NK1 Receptor Antagonist (Antiemetic)
ketoconazole Azole Antifungal
Type
aprepitant Prescription
ketoconazole Over-the-Counter
Summary
aprepitant

Aprepitant (Emend) is a medicine that helps prevent nausea and vomiting. It belongs to a class of drugs called NK1 receptor antagonists.

ketoconazole

Ketoconazole shampoo is an antifungal medicine. It treats a fungal infection on your skin.

What It Treats
aprepitant

Aprepitant is used to prevent nausea and vomiting caused by chemotherapy. It can be used for both strong and moderate chemotherapy treatments. It is also used to prevent nausea and vomiting after surgery in adults.

ketoconazole

This shampoo treats tinea versicolor, a fungal infection. This infection can cause patches on your skin that are lighter or darker than the surrounding skin. These patches may appear on your trunk, neck, arms, and upper thighs.

How It Works
aprepitant

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.

ketoconazole

Ketoconazole is an antifungal medicine. It works by stopping the growth of the fungus. This helps to clear up the infection.

Common Side Effects
aprepitant
  • Tiredness
  • Diarrhea
  • Weakness
  • Upset stomach
  • Stomach pain
ketoconazole

No common side effects listed.

FAERS Reports
aprepitant
  • Feeling sick to your stomach 2,147
  • Tiredness 1,769
  • Fever 1,589
  • Diarrhea 1,543
  • Difficulty breathing 1,508
ketoconazole
  • Feeling tired 929
  • Itching 902
  • Feeling sick to your stomach 834
  • Skin breakout 802
  • Loose stool 760
Serious Warnings
aprepitant

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.

ketoconazole

You should not use this shampoo if you are allergic to ketoconazole or any of the other ingredients.

Pregnancy
aprepitant

There is not enough information about the safety of aprepitant during pregnancy. Talk to your doctor if you are pregnant or plan to become pregnant. It is not known if aprepitant passes into breast milk, so discuss breastfeeding with your doctor.

ketoconazole

It is not known if ketoconazole shampoo can harm an unborn baby. Talk to your doctor if you are pregnant or breastfeeding before using this medicine.

Also Compare, Nearby Drugs

How to Read This aprepitant vs ketoconazole Comparison

aprepitant is classified in the NK1 Receptor Antagonist (Antiemetic) drug class, while ketoconazole sits within the Azole Antifungal class. Drugs from different classes work through distinct mechanisms, so a head-to-head comparison illustrates trade-offs rather than equivalence. Both drugs are split between OTC and prescription status, which affects access and supervision.

Adverse event totals above are pulled from the FDA's Adverse Event Reporting System (FAERS). For these top-ranked reactions alone, aprepitant has 8,556 submissions while ketoconazole has 4,227. Those figures reflect cumulative reporting volume, not per-patient risk, so older, widely dispensed drugs typically look worse on count alone. These two drugs have a known moderate interaction flagged in FDA labeling, attributed to ketoconazole strongly blocks the enzymes that clear aprepitant from your body, causing drug levels to rise.. Serious warnings, pregnancy guidance, and contraindications can differ even when indications overlap.

A table cannot substitute for clinical judgment. Effectiveness, tolerability, drug-drug interactions with your other medications, kidney and liver function, pregnancy status, insurance formulary, and price all feed into a decision that only a licensed prescriber can make responsibly. Data here is sourced from FDA Structured Product Labels (SPL) and FAERS, both of which update as manufacturers and clinicians submit new information. This page is for educational purposes only, is not medical advice, and should not be used to self-switch between aprepitant and ketoconazole - always consult your physician or pharmacist first.

Important: This comparison is for informational purposes only. Drug effects vary between individuals. Always consult your doctor or pharmacist for personalized medical advice.