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Ketoconazole

Generic name: ketoconazole [ KEE-toe-KON-a-zole ]
Brand name: Nizoral
Dosage form: oral tablet (200 mg)
Drug class: Azole antifungals

Medically reviewed by Drugs.com on Feb 14, 2024. Written by Cerner Multum.

What is ketoconazole?

Ketoconazole is an antifungal medication that is used to treat certain infections caused by fungus.

ketoconazole should be used only when you cannot use other antifungal medications. Ketoconazole can cause serious harm to your liver that may result in liver transplant or cause death.

Ketoconazole is not for use in treating fungal infections of the fingernails or toenails. This medicine is also not for use in treating prostate cancer or Cushing syndrome.

Ketoconazole may also be used for purposes not listed in this medication guide.

Ketoconazole side effects

Get emergency medical help if you have signs of an allergic reaction (hives, fever, chest pain, difficult breathing, swelling in your face or throat) or a severe skin reaction (fever, sore throat, burning eyes, skin pain, red or purple skin rash with blistering and peeling).

Ketoconazole may cause serious side effects. Call your doctor at once if you have:

Common side effects of ketoconazole may include:

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Warnings

ketoconazole should be used only when you cannot use other antifungal medications. Ketoconazole can cause serious harm to your liver that may result in liver transplant or cause death.

Call your doctor at once if you have any signs of liver damage, such as nausea, vomiting, stomach pain, fever, tiredness, loss of appetite, dark urine, clay-colored stools, or jaundice (yellowing of the skin or eyes).

Tell your doctor about all your current medicines and any you start or stop using. Many drugs can interact, and some drugs should not be used together.

Ketoconazole can also cause a serious heart problem. Call your doctor right away if you have fast or pounding heartbeats, shortness of breath, and sudden dizziness.

Before taking this medicine

You should not use ketoconazole if you are allergic to it, or if you have liver disease.

Some medicines can cause unwanted or dangerous effects when used with ketoconazole. Your doctor may change your treatment plan if you also use:

Tell your doctor if you have ever had:

It is not known whether this medicine will harm an unborn baby. Tell your doctor if you are pregnant.

You should not breast-feed while using this medicine.

Do not give this medicine to a child without medical advice.

How should I take ketoconazole?

Your doctor will perform blood tests to make sure you do not have conditions that would prevent you from safely using ketoconazole.

Follow all directions on your prescription label and read all medication guides or instruction sheets. Your doctor may occasionally change your dose. Use the medicine exactly as directed.

You may need to use ketoconazole for up to 6 months.

Use this medicine for the full prescribed length of time, even if your symptoms quickly improve. Skipping doses can increase your risk of infection that is resistant to medication. Ketoconazole will not treat a viral infection such as the flu or a common cold.

While using ketoconazole, you may need frequent blood tests to check your liver function.

Store at room temperature away from moisture, heat, and light.

Do not share this medicine with another person, even if they have the same symptoms you have.

What happens if I miss a dose?

Take the medicine as soon as you can, but skip the missed dose if it is almost time for your next dose. Do not take two doses at one time.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

What should I avoid while taking ketoconazole?

Do not drink alcohol. Dangerous side effects could occur.

Ketoconazole could make you sunburn more easily. Avoid sunlight or tanning beds. Wear protective clothing and use sunscreen (SPF 30 or higher) when you are outdoors.

What other drugs will affect ketoconazole?

Some medicines can make it harder for your body to absorb ketoconazole. If you take an antacid, take it 1 hour before or 2 hours after you take ketoconazole. Tell your doctor if you also take a stomach acid reducer, such as Nexium, Prevacid, Prilosec, Protonix, Zantac, and others.

Sometimes it is not safe to use certain medications at the same time. Some drugs can affect your blood levels of other drugs you take, which may increase side effects or make the medications less effective.

Ketoconazole can cause a serious heart problem. Your risk may be higher if you also use certain other medicines for infections, asthma, heart problems, high blood pressure, depression, mental illness, cancer, malaria, or HIV.

Many drugs can affect ketoconazole. This includes prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible interactions are listed here. Tell your doctor about all your current medicines and any medicine you start or stop using.

Frequently asked questions

Further information

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.