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Overview: Ketoconazole is a tablet taken to treat serious fungal infections. It stops fungi from growing. Common side effects include nausea, vomiting, and stomach pain. Serious side effects are rare, but can include liver problems. Ketoconazole interacts with many other medicines. Tell your healthcare provider about all of the medicines you take before taking ketoconazole.

Uses

What is ketoconazole used for?

Ketoconazole is commonly used to treat serious fungal infections. It is not recommended for treating fungal nail infections, fungal skin infections, or fungal infections in the mouth or genitals.

Ketoconazole may also be used for other conditions as determined by your healthcare provider.

How does ketoconazole work (mechanism of action)?

Ketoconazole is an antifungal medicine that stops the fungus from growing and causing the infection.

How is ketoconazole supplied (dosage forms)?

Brand and other names

  • Nizoral

Dosage form and strengths

  • 200 mg oral tablets

Ketoconazole is also available as a cream, foam, or shampoo for use on the scalp or skin. See Ketoconazole topical for more information.

How should I store ketoconazole?

Ketoconazole should be stored at room temperature, between 68 F to 77 F (20 C to 25 C). It can be exposed to temperatures between 59 F to 86 F (15 C to 30 C) for shorter periods of time, such as when transporting it. Store in a cool, dry place. Protect from moisture.

Side Effects

What are the most common side effects of ketoconazole?

The most common side effects of ketoconazole are listed below. Tell your healthcare provider if you have any of these side effects that bother you.

  • Nausea, vomiting, or stomach pain
  • Headache
  • Diarrhea
  • Itching

There may be other side effects of ketoconazole that are not listed here. Contact your healthcare provider if you think you are having a side effect of a medicine. In the U.S., you can report side effects to the FDA at www.fda.gov/medwatch or by calling 800-FDA-1088. In Canada, you can report side effects to Health Canada at www.health.gc.ca/medeffect or by calling 866-234-2345.

What are the serious side effects of ketoconazole?

While less common, the most serious side effects of ketoconazole are described below, along with what to do if they happen.

Severe Allergic Reactions. Ketoconazole may cause allergic reactions, which can be serious. Stop taking ketoconazole and get help right away if you have any of the following symptoms of a serious allergic reaction.

  • Breathing problems or wheezing
  • Racing heart
  • Fever or general ill feeling
  • Swollen lymph nodes
  • Swelling of the face, lips, mouth, tongue, or throat
  • Trouble swallowing or throat tightness
  • Itching, skin rash, or pale red bumps on the skin called hives
  • Nausea or vomiting
  • Dizziness, feeling lightheaded, or fainting
  • Stomach cramps
  • Joint pain

Liver Damage. Liver damage, also called hepatotoxicity, can happen when taking ketoconazole. This can be serious or even life-threatening. Call your healthcare provider right away if you have any of the following symptoms of liver damage.

  • Nausea or vomiting
  • Stomach or belly pain
  • Fever
  • Weakness or unusual tiredness
  • Itching
  • Loss of appetite
  • Light-colored poop
  • Dark-colored urine (pee)
  • Your skin or the whites of your eyes turning yellowish in color (also called jaundice)

Heart Rhythm Changes. Ketoconazole may cause a rare, dangerous heart rhythm problem called QT prolongation and torsade de pointes. Some people have a higher risk of this, including people who are older, have other people in their family who have had these conditions, have low potassium or magnesium levels, or who take some medicines for other heart rhythm problems.

Reduced Adrenal Function. High doses of ketoconazole can cause your body’s adrenal glands to stop making as much cortisol (the stress hormone). This is known as adrenal insufficiency. Adrenal insufficiency can get worse if your body is under stress because of fever, surgery, or trauma. Tell your healthcare provider if you have any of the following symptoms of adrenal insufficiency.

  • Nausea and vomiting
  • Weakness, tiredness, or lack of energy
  • Low blood pressure

Warnings & Precautions

Who should not use ketoconazole?

Allergies to Ingredients. People who are allergic to any of the following should not take ketoconazole.

  • Ketoconazole
  • Nizoral
  • Any of the ingredients in the specific product dispensed

Your pharmacist can tell you all of the ingredients in the specific ketoconazole products they stock.

Drug Interactions. Ketoconazole should not be taken while you are using certain other medicines. Before taking ketoconazole, tell your healthcare provider about any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using. See the Interactions section for more details.

Liver Problems. Ketoconazole should not be used if your liver is not working as well as it should be. If there is a concern about the health of your liver, your healthcare provider may do tests to determine if it is working well enough to take this medicine.

What should I know about ketoconazole before using it?

Do not take ketoconazole unless it has been prescribed to you by a healthcare provider. Take it as prescribed.

Do not share ketoconazole with other people, even if they have the same condition as you. It may harm them.

Keep ketoconazole out of the reach of children.

Do not stop taking ketoconazole without first talking to your healthcare provider.

If you take any medicine to reduce stomach acid or treat heartburn and indigestion, talk with your healthcare provider about the best way to take ketoconazole. These medicines may affect how well your body absorbs ketoconazole. You may be able to take ketoconazole with an acidic beverage, like a non-diet cola. See the Interactions section for more details.

Keep all appointments for bloodwork while you are taking ketoconazole. 

What should I tell my healthcare provider before using ketoconazole?

Tell your healthcare provider about all of your health conditions and any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using. This will help them determine if ketoconazole is right for you.

In particular, make sure that you discuss any of the following.

Current and Past Health Conditions. Tell your healthcare provider if you have any of the following.

  • Liver problems
  • An abnormal heart rhythm problem called congenital long QT syndrome
  • A condition called adrenal insufficiency, which is when your adrenal glands do not produce enough hormones
  • A condition called hypochlorhydria, which is when your stomach produces a low amount of acid
  • Any upcoming major surgeries

Pregnancy. It is not known if or how ketoconazole could affect pregnancy or harm an unborn baby. Tell your healthcare provider if you are or plan to become pregnant.

Breastfeeding. Do not take ketoconazole while you are breastfeeding. Ketoconazole can pass into breast milk. Tell your healthcare provider if you are breastfeeding or plan to breastfeed. Your healthcare provider will advise you if you should stop breastfeeding or stop ketoconazole.

Interactions

Does ketoconazole interact with foods or drinks?

Avoid eating or drinking anything with grapefruit or grapefruit juice while taking ketoconazole. Grapefruit juice can raise the levels of ketoconazole in your blood, which may increase the risk and severity of side effects.

Do not drink alcohol while taking ketoconazole. Drinking alcohol while taking ketoconazole may increase your risk of liver damage.

Does ketoconazole interact with other medicines (drug interactions)?

Ketoconazole interacts with many other medicines. Always tell your healthcare provider about any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using.

In particular, make sure that you discuss if you are using any of the following before taking ketoconazole.

  • Medicines that can cause QT prolongation, which is a potentially dangerous heart rhythm problem, such as pimozide or quinidine
  • A statin, such as atorvastatin (Lipitor and others), lovastatin, simvastatin, or rosuvastatin (Crestor), which is a medicine to lower cholesterol
  • An ergot, such as ergotamine (Ergomar) or dihydroergotamine (Migranal or Trudhesa), which is a medicine used to treat migraine
  • A medicine to reduce stomach acid, such as an antacid, an H2 blocker (such as cimetidine, famotidine, or nizatidine), or a proton pump inhibitor (such as esomeprazole, lansoprazole, omeprazole, pantoprazole, or rabeprazole)
  • Digoxin (Lanoxin), which is a medicine used to treat irregular heartbeat and some types of heart failure
  • A benzodiazepine, such as alprazolam (Xanax), clonazepam (Klonopin), diazepam (Valium and others), lorazepam (Ativan and others), midazolam, or triazolam (Halcion), which is a medicine used for anxiety, muscle spasms, or seizures
  • Diltiazem, verapamil, nifedipine, nicardipine, nisoldipine, or felodipine, which is a medicine used for high blood pressure and other conditions
  • Lurasidone (Latuda), which is a medicine for certain mental health conditions
  • An opioid, such as oxycodone, morphine, codeine, methadone, or fentanyl, which is a medicine used for certain types of pain
  • Disopyramide, dronedarone (Multaq), or dofetilide, which is a medicine used to control your heart rate or rhythm (antiarrhythmic)
  • Ranolazine, which is used to treat chest pain
  • Irinotecan (Camptosar), which is used for certain cancers
  • Tolvaptan (Samsca, Jynarque), which is used for low sodium levels
  • Eplerenone (Inspra), which is commonly used for heart failure and high blood pressure
  • Colchicine, which is commonly used for gout
  • Isoniazid (INH) or rifampin (Rifadin), which is a medicine used to treat tuberculosis
  • Rifabutin (Mycobutin), which is a medicine used to prevent Mycobacterium avium complex infection
  • Any medicine for seizures, such as carbamazepine, phenytoin, or phenobarbital
  • Efavirenz, nevirapine, or ritonavir (Norvir), which is a medicine for HIV

Ketoconazole may alter the blood levels of many other medicines, and vice versa. Tell your healthcare provider about all medicines that you take or have recently taken.

This may not be a complete list of medicines that can interact with ketoconazole. Always check with your healthcare provider.

Does interact with other drugs you are taking?

Enter your medication into the WebMD interaction checker

Overdose/Missed Dose

What should I do if I accidentally use too much ketoconazole?

If you or someone else has used too much ketoconazole, get medical help right away, call 911, or contact a Poison Control center at 800-222-1222.

What should I do if I miss a dose of ketoconazole?

It is important to complete your prescribed course of ketoconazole, even if your symptoms get better or go away. This will reduce the risk that future infections are resistant to ketoconazole or other similar medicines.

If you miss a dose, take it as soon as you remember. If it is almost time for your next dose, skip the missed dose and only take the next dose. Do not take double or extra doses.