Ketoconazole

Description

Ketoconazole is an antifungal medication belonging to the azole class. It works by stopping fungi from growing and spreading in the body. Doctors may prescribe these tablets to treat systemic fungal infections affecting areas such as the lungs, bloodstream, or other internal organs. They are only prescribed when other antifungal medicines cannot be used or have not worked, due to the risk of serious side effects. Ketoconazole tablets should not be used for common yeast infections or fungal infections of the skin or nails.

Directions

Ketoconazole is taken as 200 mg by mouth once daily, with or without food, as directed by a healthcare provider. The dosage may change based on your overall condition or as recommended, as some cases may require a higher dose. It’s important to follow the dosing schedule, and avoid stopping or changing the dose without a doctor’s approval. Regular monitoring and follow-up may be necessary to check for possible side effects or changes in liver function.

Ingredients

This medication contains the active ingredient Ketoconazole.

Contraindications

Avoid giving or taking this medication if any of the following apply:

• Hypersensitivity to any ingredients in the medication
• Acute or chronic liver disease
• Using it with certain heart medications (dofetilide, quinidine, cisapride, pimozide, disopyramide, dronedarone)
• Using it with some antipsychotics (lurasidone)
• Using it with specific sedatives (oral midazolam, oral triazolam, alprazolam)
• Using it with ergot alkaloids (dihydroergotamine, ergometrine, ergotamine, methylergometrine)
• Using it with certain blood pressure and heart drugs (felodipine, nisoldipine, ranolazine, tolvaptan, eplerenone)
• Using it with cholesterol-lowering medications (lovastatin, simvastatin)
• Using it with methadone, irinotecan, or colchicine

Cautions

• Before using or administering this medication you may want to consult a healthcare provider about the following:
• Any existing health conditions
• Any allergies
• A list of all medications you are currently taking
• Whether you are pregnant or breastfeeding

• Ketoconazole tablets are not recommended for common fungal infections like athlete’s foot, ringworm, or yeast infections. This medication should only be used if no other effective antifungal treatment is available and the benefits outweigh the serious risks.
• Serious liver damage, including liver failure and death, has been reported with this medication, even in people without previous liver problems.
• Ketoconazole can also affect heart rhythm by prolonging the QT interval. Taking it with certain medications may lead to dangerous heart problems like torsades de pointes, a potentially fatal irregular heart rhythm.
• At higher doses (400 mg or more), this drug can lower the body’s production of adrenal hormones. If you already have adrenal problems or are under physical stress (like surgery), your doctor may need to monitor your adrenal function during treatment.
• This medication has been used for prostate cancer and Cushing’s syndrome, but these uses are not FDA-approved. In high doses, this drug has been linked to serious side effects and even deaths in patients with other underlying conditions.
• Ketoconazole can also reduce testosterone levels, especially at higher doses. This may cause side effects like decreased sex drive, breast enlargement in men, or low sperm count. Testosterone levels usually return to normal after stopping treatment.
• Ketoconazole interacts with many other drugs. It can make other medications stronger or weaker, sometimes leading to dangerous side effects.
• Avoid antacids or medications that reduce stomach acid when taking this medication, as they can interfere with how your body absorbs it. If needed, take these types of drugs at least 1 to 2 hours before or after your dose.
• This medicine should not be used during pregnancy unless absolutely necessary. It may harm an unborn baby or cause complications during birth. It also passes into breast milk, so women taking it should not breastfeed.

Side Effects

The most common side effects may include nausea, vomiting, abdominal pain, and diarrhea. Other reported side effects include headache, dizziness, fatigue, and changes in appetite. Skin-related reactions such as rash, itching, or dry skin are also possible, along with occasional hormonal effects like breast swelling in men or menstrual changes in women.

More serious adverse effects, though rare, include liver problems such as hepatitis, yellowing of the skin or eyes (jaundice), and in severe cases, liver failure. Post-marketing reports have identified allergic reactions, low platelet counts, and increased intracranial pressure, especially in infants. Ketoconazole may also affect adrenal or reproductive hormones at high doses.

References

1. Nizoral Product Monograph. Titusville, NJ: Janssen Pharmaceuticals, Inc.; 2014.
2. Ketoconazole Tablets Drug Label Information. Melville, NY: Amici Pharma, Inc.; 2025.

About Dr. Gerardo Sison (Page Author)

An honors graduate of the University of Florida, Dr. Sison started his pharmacy career in a community setting, extending his services to hospitals and clinics over time. He has also worked in medication therapy management, advising patients on proper medication use for their chronic health conditions. Read More....