dutasteride vs ketoconazole

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

minor Known Drug Interaction

Concomitant treatment with ketoconazole (a strong inhibitor of CYP3A4) resulted in increases in the C max and AUC of tamsulosin by factors of 2.2 and 2.8, respectively. Since CYP2D6 PMs cannot be readily identified and the potential for significant increase in tamsulosin exposure exists when tamsulosin 0.4 mg is coadministered with strong CYP3A4 inhibitors in CYP2D6 PMs, tamsulosin 0.4 mg capsules should not be used in combination with strong inhibitors of CYP3A4 (e.g., ketoconazole).

Drug Class
dutasteride 5-Alpha Reductase Inhibitor
ketoconazole Azole Antifungal
Type
dutasteride Prescription
ketoconazole Over-the-Counter
Summary
dutasteride

Dutasteride and tamsulosin hydrochloride capsules contain two medicines to treat enlarged prostate in men. They help improve symptoms like frequent urination.

ketoconazole

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

What It Treats
dutasteride

This medicine treats benign prostatic hyperplasia (BPH), also known as enlarged prostate, in men. It helps with symptoms like needing to urinate often, especially at night. It is for men who have an enlarged prostate causing these problems. This medicine is not approved to prevent prostate cancer.

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
dutasteride

Dutasteride lowers a hormone called dihydrotestosterone (DHT) that causes the prostate to grow. Tamsulosin relaxes the muscles in the prostate and bladder. This combination helps urine flow more easily.

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
dutasteride
  • Problems with ejaculation
  • Impotence (trouble getting or keeping an erection)
  • Decreased sex drive
  • Dizziness
  • Breast enlargement or tenderness
ketoconazole

No common side effects listed.

FAERS Reports
dutasteride
  • Dyspnoea 1,233
  • Fatigue 1,142
  • Dizziness 985
  • Asthenia 933
  • Diarrhoea 896
ketoconazole
  • Fatigue 929
  • Pruritus 902
  • Nausea 834
  • Rash 802
  • Diarrhoea 760
Serious Warnings
dutasteride

This medicine can cause dizziness or fainting, so be careful to avoid falls or injuries. Do not take this medicine with other alpha-blockers, as this can lower your blood pressure too much. This medicine can affect PSA levels, which are used to screen for prostate cancer. Tell your doctor you are taking this medicine before any PSA tests. This medicine may increase the risk of high-grade prostate cancer. Pregnant women should not handle this medicine.

ketoconazole

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

Pregnancy
dutasteride

This medicine is not for use in women. It can cause birth defects in a male fetus if a pregnant woman is exposed to it. Pregnant women or women who may become pregnant should not handle these capsules.

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 dutasteride vs ketoconazole Comparison

dutasteride is classified in the 5-Alpha Reductase Inhibitor 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, dutasteride has 5,189 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 minor interaction flagged in FDA labeling, attributed to ketoconazole blocks the body's ability to break down the medication, which can cause the drug to build up to unsafe levels.. Serious warnings, pregnancy guidance, and contraindications can differ even when indications overlap.

A table cannot represent individual circumstances. Data here is sourced from FDA Structured Product Labels (SPL) and FAERS, both of which update as manufacturers and clinicians submit new information. This registry does not provide medical, treatment, substitution, or medication-change directions for dutasteride or ketoconazole.

Registry boundary: This comparison displays source-record fields and does not provide individualized medical direction.