Medically reviewed by Drugs.com. Last updated on Mar 13, 2022.
Ketoconazole tablets should only be used when other antifungal therapies are unavailable or not tolerated, and the potential benefits of treatment outweigh its risks. Serious hepatotoxicity, including cases with a fatal outcome or requiring liver transplantation has occurred with the use of oral ketoconazole, even in patients with no obvious risk factors for liver disease. Patients who receive this drug should be informed by the physician of the risk and should be closely monitored. Coadministration of ketoconazole with dofetilide, quinidine, pimozide, cisapride, methadone, disopyramide, dronedarone, and ranolazine is contraindicated, as ketoconazole can cause increased plasma concentrations of these drugs and may prolong QT intervals, sometimes resulting in life-threatening ventricular dysrhythmias such as torsades de pointes .
Commonly used brand name(s)
In the U.S.
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Therapeutic Class: Antifungal
Chemical Class: Imidazole
Uses for ketoconazole
Ketoconazole is used to treat serious fungal or yeast infections, such as candidiasis (thrush, oral thrush), blastomycosis (Gilchrist's disease), coccidioidomycosis (Valley fever, San Joaquin Valley fever), histoplasmosis (Darling's disease), chromoblastomycosis (chromomycosis), or paracoccidioidomycosis (South American blastomycosis, Lutz-Splendore-Almeida disease). Ketoconazole works by killing the fungus or yeast, or preventing its growth.
Ketoconazole is also used to treat parasitic fungal infections on the skin (such as athlete's foot or ringworm) that cannot be treated with topical medicine or griseofulvin, or for patients who cannot take griseofulvin.
Ketoconazole is available only with your doctor's prescription.
Before using ketoconazole
In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For ketoconazole, the following should be considered:
Tell your doctor if you have ever had any unusual or allergic reaction to ketoconazole or any other medicines. Also tell your health care professional if you have any other types of allergies, such as to foods, dyes, preservatives, or animals. For non-prescription products, read the label or package ingredients carefully.
Appropriate studies have not been performed on the relationship of age to the effects of ketoconazole in children younger than 2 years of age. Safety and efficacy have not been established.
No information is available on the relationship of age to the effects of ketoconazole in geriatric patients.
There are no adequate studies in women for determining infant risk when using this medication during breastfeeding. Weigh the potential benefits against the potential risks before taking this medication while breastfeeding.
Interactions with medicines
Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking ketoconazole, it is especially important that your healthcare professional know if you are taking any of the medicines listed below. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.
Using ketoconazole with any of the following medicines is not recommended. Your doctor may decide not to treat you with this medication or change some of the other medicines you take.
- Ergoloid Mesylates
- Irinotecan Liposome
- Isavuconazonium Sulfate
Using ketoconazole with any of the following medicines is usually not recommended, but may be required in some cases. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.
- Ado-Trastuzumab Emtansine
- Aluminum Carbonate, Basic
- Aluminum Hydroxide
- Aluminum Phosphate
- Arsenic Trioxide
- Calcium Carbonate
- Dabigatran Etexilate
- Dihydroxyaluminum Aminoacetate
- Dihydroxyaluminum Sodium Carbonate
- Doxorubicin Hydrochloride Liposome
- Inotuzumab Ozogamicin
- Magnesium Carbonate
- Magnesium Hydroxide
- Magnesium Oxide
- Magnesium Trisilicate
- Morphine Sulfate Liposome
- Sirolimus Protein-Bound
- Sodium Bicarbonate
- Sodium Phosphate
- Sodium Phosphate, Dibasic
- Sodium Phosphate, Monobasic
- St John's Wort
- Vincristine Sulfate Liposome
Using ketoconazole with any of the following medicines may cause an increased risk of certain side effects, but using both drugs may be the best treatment for you. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.
- Aripiprazole Lauroxil
Interactions with food/tobacco/alcohol
Certain medicines should not be used at or around the time of eating food or eating certain types of food since interactions may occur. Using alcohol or tobacco with certain medicines may also cause interactions to occur. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.
Using ketoconazole with any of the following is usually not recommended, but may be unavoidable in some cases. If used together, your doctor may change the dose or how often you use ketoconazole, or give you special instructions about the use of food, alcohol, or tobacco.
- Grapefruit Juice
Other medical problems
The presence of other medical problems may affect the use of ketoconazole. Make sure you tell your doctor if you have any other medical problems, especially:
- Achlorhydria (absence of stomach acid)—May not be absorbed from the stomach in patients with this condition.
- Adrenal problems or
- Heart disease, history of or
- Heart rhythm problems (eg, QT prolongation), or history of—These conditions may cause side effects to become worse.
- Liver disease, acute or chronic—Should not be used in patients with this condition.
Proper use of ketoconazole
Take ketoconazole exactly as directed by your doctor. Do not take more of it, do not take it more often, and do not take it for a longer time than your doctor ordered. Do not stop taking ketoconazole without checking first with your doctor.
Ketoconazole should come with a Medication Guide. Read and follow these instructions carefully. Ask your doctor if you have any questions.
It is best to take ketoconazole with food.
Keep using ketoconazole for the full treatment time, even if you feel better after the first few doses. Your infection may not clear up if you stop using the medicine too soon.
If you are taking ketoconazole together with an antacid-containing aluminum, it should be taken with an acidic beverage (such as non-diet cola). Antacid-containing aluminum should be taken at least 1 hour before or 2 hours after taking ketoconazole.
The dose of ketoconazole will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of ketoconazole. If your dose is different, do not change it unless your doctor tells you to do so.
The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.
- For oral dosage form (tablets):
- For fungal infections:
- Adults—At first, 200 milligrams (mg) once a day. Your doctor may increase your dose as needed.
- Children 2 years of age and older—Dose is based on body weight and must be determined by your doctor. The dose is usually 3.3 to 6.6 milligrams (mg) per kilogram (kg) of body weight per day.
- Children younger than 2 years of age—Use and dose must be determined by your doctor.
- For fungal infections:
If you miss a dose of ketoconazole, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not double doses.
Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light. Keep from freezing.
Keep out of the reach of children.
Do not keep outdated medicine or medicine no longer needed.
Ask your healthcare professional how you should dispose of any medicine you do not use.
Precautions while using ketoconazole
It is very important that your doctor check your or your child's progress at regular visits to make sure ketoconazole is working properly. Blood tests may be needed to check for unwanted effects.
If your or your child's symptoms do not improve, or if they become worse, check with your doctor. You may need to take ketoconazole for several months before your infection gets better.
Do not use ketoconazole together with alprazolam, cisapride, colchicine, disopyramide, dofetilide, dronedarone, eplerenone, felodipine, irinotecan, lovastatin, lurasidone, methadone, nisoldipine, oral midazolam, pimozide, quinidine, ranolazine, simvastatin, terfenadine, tolvaptan, triazolam, or ergot medicines (such as dihydroergotamine, ergometrine, ergotamine, methylergometrine). Using these medicines together may cause serious unwanted effects.
Liver problems may occur while you are taking ketoconazole. Check with your doctor right away if you are having more than one of these symptoms: abdominal or stomach pain or tenderness, clay-colored stools, dark urine, decreased appetite, fever, headache, itching, loss of appetite, nausea and vomiting, skin rash, swelling of the feet or lower legs, unusual tiredness or weakness, or yellow eyes or skin.
Contact your doctor right away if you have any changes to your heart rhythm. You might feel dizzy or faint, or you might have a fast, pounding, or uneven heartbeat. Make sure your doctor knows if you or anyone in your family has ever had a heart rhythm problem such as QT prolongation.
Ketoconazole may cause serious allergic reactions, including anaphylaxis. Anaphylaxis can be life-threatening and requires immediate medical attention. Call your doctor right away if you have a rash, itching, trouble breathing, trouble swallowing, or any swelling of your hands, face, or mouth while you are using ketoconazole.
Avoid drinking alcohol while you are using ketoconazole.
Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines and herbal or vitamin supplements.
Ketoconazole side effects
Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.
Check with your doctor immediately if any of the following side effects occur:
- Back, leg, or stomach pains
- black, tarry stools
- bleeding gums
- blood in the urine or stools
- blurred vision
- burning, crawling, itching, numbness, prickling, "pins and needles", or tingling feelings
- change in color vision
- change in the ability to see colors, especially blue or yellow
- chest pain
- dark urine
- difficulty seeing at night
- difficulty swallowing
- fast heartbeat
- general body swelling
- increased sensitivity of the eyes to sunlight
- joint pain, stiffness, or swelling
- light-colored stools
- loss of appetite
- mood or mental changes
- nausea or vomiting, severe
- painful or difficult urination
- pale skin
- pinpoint red spots on the skin
- puffiness or swelling of the eyelids or around the eyes, face, lips, or tongue
- redness of the skin
- skin rash, hives, itching
- sore throat
- sores, ulcers, or white spots on the lips or in the mouth
- swelling of the eyelids, face, lips, hands, or feet
- swollen glands
- tightness in the chest
- trouble sleeping
- troubled breathing or swallowing
- unusual bleeding or bruising
- unusual tiredness or weakness
- vision changes
- yellow eyes or skin
Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:
- Change in number of sperm and their ability to move
- decreased interest in sexual intercourse
- hair loss or thinning of the hair
- inability to have or keep an erection
- loss in sexual ability, desire, drive, or performance
- sleepiness or unusual drowsiness
- swelling of the breasts or breast soreness for both female and male
Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.
Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.
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