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fluconazole vs ketoconazole

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

Drug Class
fluconazole Azole Antifungal
ketoconazole Azole Antifungal
Type
fluconazole Prescription
ketoconazole Over-the-Counter
Summary
fluconazole

Fluconazole is an antifungal medicine. It is used to treat infections caused by fungus.

ketoconazole

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

What It Treats
fluconazole

Fluconazole treats vaginal yeast infections. It also treats yeast infections in the mouth and esophagus. Fluconazole can also treat urinary tract infections, peritonitis, systemic Candida infections, and pneumonia. It can also treat cryptococcal meningitis. Fluconazole can also prevent candidiasis in patients undergoing bone marrow transplantation.

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
fluconazole

Fluconazole works by stopping the growth of fungi. It blocks the fungus from producing a substance it needs to grow. This helps to clear up the infection.

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
fluconazole
  • Headache
  • Nausea
  • Abdominal pain
ketoconazole

No common side effects listed.

FAERS Reports
fluconazole
  • Medicine not working 4,932
  • Using medicine for unapproved purpose 4,329
  • Fever 4,121
  • Feeling sick to your stomach 3,695
  • Loose stools 3,536
ketoconazole
  • The medicine did not work 1,582
  • Using the medicine for something it's not approved for 1,174
  • Feeling tired 929
  • Itching 902
  • Feeling sick to your stomach 834
Serious Warnings
fluconazole

Coadministration of other drugs known to prolong the QT interval and which are metabolized via the enzyme CYP3A4 such as erythromycin, pimozide, and quinidine are contraindicated in patients receiving fluconazole.

ketoconazole

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

Pregnancy
fluconazole

Tell your doctor if you are pregnant or plan to become pregnant. Fluconazole may not be safe for your baby. Talk to your doctor about breastfeeding while taking fluconazole.

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 fluconazole vs ketoconazole Comparison

fluconazole is classified in the Azole Antifungal drug class, while ketoconazole sits within the Azole Antifungal class. Because both drugs share the same classification, they are often considered interchangeable in theory — but clinical outcomes rarely track that cleanly. 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, fluconazole has 20,613 submissions while ketoconazole has 5,421. Those figures reflect cumulative reporting volume — not per-patient risk — so older, widely dispensed drugs typically look worse on count alone. No direct interaction between these two drugs is listed in our FDA-derived dataset, though co-prescription still warrants pharmacist review. 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 fluconazole 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.