Ketoconazole
Warning
Ketoconazole can cause serious (possibly fatal) side effects and drug interactions. It should only be used when other treatments have not worked, are not available, or cannot be taken by you. Discuss the risks and benefits of this medication, as well as other effective and possibly safer treatments for fungal infections, with your doctor.
Ketoconazole has rarely caused very serious (possibly fatal) liver problems. Get medical help right away if you develop symptoms of liver problems, including nausea/vomiting that doesn't stop, stomach/abdominal pain, dark urine, yellowing eyes/skin, loss of appetite, or light colored stools. To reduce your risk for liver problems, your doctor should obtain liver function tests every week while you are taking this medication. Do not drink alcoholic beverages while taking ketoconazole because alcohol increases the risk of serious liver problems. See also Notes section.
Ketoconazole must not be used with certain other medications because a serious, possibly fatal, drug interaction may occur. Ketoconazole interacts with drugs such as disopyramide, dofetilide, dronedarone, methadone, pimozide, quinidine, ranolazine, among others. These interactions may increase the risk of a certain condition that affects the heart rhythm (QT prolongation). QT prolongation can rarely cause serious (rarely fatal) fast/irregular heartbeat and other symptoms (such as severe dizziness, fainting) that need medical attention right away. Tell your doctor and pharmacist about all the medications and products you may be taking before you start ketoconazole treatment. See also Precautions section.
Precautions
See also Side Effects section.
Before taking ketoconazole, tell your doctor or pharmacist if you are allergic to it; or to levoketoconazole; or to other azole antifungal drugs (such as fluconazole, itraconazole); or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.
Before using this medication, tell your doctor or pharmacist your medical history, especially of: liver problems, alcohol use, low testosterone levels, decreased adrenal gland function problems (such as low cortisol levels, Addison's disease, adrenal insufficiency), little or no stomach acid production (achlorhydria).
Ketoconazole may cause a condition that affects the heart rhythm (QT prolongation). QT prolongation can rarely cause serious (rarely fatal) fast/irregular heartbeat and other symptoms (such as severe dizziness, fainting) that need medical attention right away.
The risk of QT prolongation may be increased if you have certain medical conditions or are taking other drugs that may cause QT prolongation. Before using ketoconazole, tell your doctor or pharmacist of all the drugs you take and if you have any of the following conditions: certain heart problems (heart failure, slow heartbeat, QT prolongation in the EKG), family history of certain heart problems (QT prolongation in the EKG, sudden cardiac death).
Low levels of potassium or magnesium in the blood may also increase your risk of QT prolongation. This risk may increase if you use certain drugs (such as diuretics/"water pills") or if you have conditions such as severe sweating, diarrhea, or vomiting. Talk to your doctor about using ketoconazole safely.
Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).
Do not drink alcoholic beverages while taking this medication because alcohol increases the risk of serious liver problems. Avoiding alcoholic beverages will also decrease the risk of a rare reaction with ketoconazole that may result in flushing, headache, and nausea.
Older adults may be more sensitive to the side effects of this drug, especially QT prolongation (see above).
During pregnancy, this medication should be used only when clearly needed. Discuss the risks and benefits with your doctor.
This medication passes into breast milk. Consult your doctor before breastfeeding.
Side Effects
See also Warning section.
Nausea and vomiting may occur. If any of these effects last or get worse, tell your doctor or pharmacist promptly.
Remember that this medication has been prescribed because your doctor has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.
Tell your doctor right away if you have any serious side effects, including: headache, vision changes, mental/mood changes (such as depression, thoughts of suicide).
Although unlikely, when ketoconazole is used at high doses, it may cause an adrenal gland problem (adrenal insufficiency), a decrease in testosterone levels, and a decrease in sperm production. Ketoconazole can also worsen existing adrenal gland function problems (See also Precautions section). The adrenal gland problem may make it more difficult for your body to respond to physical stress. Before having surgery or emergency treatment, or if you get a serious illness/injury, tell your doctor or dentist that you are using this medication. Your doctor may order a blood test to monitor your adrenal gland function while you are taking ketoconazole. These effects usually go away after ketoconazole treatment is stopped. Tell your doctor right away if you have any serious side effects, including: unusual tiredness, weakness, dizziness upon standing, diarrhea, weight loss, menstrual period changes, decreased sexual interest or ability, enlarged/tender breasts in men.
Get medical help right away if you have any very serious side effects, including: fast/irregular heartbeat, severe dizziness, fainting.
A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.
This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.
In the US -
Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch.
In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.
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