Ketoconazole (oral tablets)
Pronunciation: pronunciation varies by local usage.
- Generic name
- ketoconazole
- Brand names
- NIZORAL
- Drug class
- Azole antifungal (systemic)
- Form
- Tablet, 200 mg
- Route
- Oral
- Legal status
- Prescription-only medicine
Availability and supply rules vary by country
Trade names by country: United States · Canada
Australia: · Full directory
What ketoconazole is and how it works
Ketoconazole oral tablets are an azole antifungal reserved for the treatment of certain deep (systemic) fungal infections when other effective antifungal therapies are not available or tolerated, because of serious risks including liver injury and drug interactions. (1) (2)
Oral ketoconazole carries a boxed warning for hepatotoxicity. It is not used for common skin, nail, or Candida infections. Treatment requires clinician oversight, baseline and ongoing liver function monitoring, and careful drug interaction screening.
Mechanism of action: how ketoconazole works
What ketoconazole is used for
Blastomycosis
Ketoconazole tablets may be used to treat blastomycosis when other effective antifungal therapies are not available or tolerated, as determined by the prescribing clinician. (1)
Coccidioidomycosis
Ketoconazole tablets may be used to treat coccidioidomycosis when other effective antifungal therapies are not available or tolerated, as determined by the prescribing clinician. (1)
Histoplasmosis
Ketoconazole tablets may be used to treat histoplasmosis when other effective antifungal therapies are not available or tolerated, as determined by the prescribing clinician. (1)
Chromomycosis
Ketoconazole tablets may be used to treat chromomycosis when other effective antifungal therapies are not available or tolerated, as determined by the prescribing clinician. (1)
Paracoccidioidomycosis
Ketoconazole tablets may be used to treat paracoccidioidomycosis when other effective antifungal therapies are not available or tolerated, as determined by the prescribing clinician. (1)
Before taking ketoconazole
Do not take / not appropriate for
- Acute or chronic liver disease is a contraindication — tell your prescriber, who will determine whether ketoconazole is appropriate. (all patients) (1)
- Coadministration with dofetilide, quinidine, pimozide, cisapride, methadone, disopyramide, dronedarone, or ranolazine is contraindicated — these combinations can cause life-threatening irregular heart rhythms. Tell your prescriber and pharmacist about all medicines you take so they can check for this. (contraindicated coadministration) (1)
- Coadministration with ergot alkaloids, lovastatin, simvastatin, oral midazolam, triazolam, or alprazolam is contraindicated. Tell your prescriber and pharmacist about all medicines you take so they can check for this. (contraindicated coadministration) (1)
- Ketoconazole tablets are not indicated for skin, nail (onychomycosis), or Candida infections. (indications) (1) (2)
Tell your clinician about
- Any history of liver problems or abnormal liver tests.
- All prescription and over‑the‑counter medicines you take, so your prescriber can check for the contraindicated combinations above.
- If you are pregnant, planning to become pregnant, or breastfeeding (see Special populations).
- Any history of adrenal gland insufficiency or borderline adrenal function, or if you are currently under prolonged stress (major surgery, intensive care, etc.).
How to take ketoconazole
- Take ketoconazole exactly as prescribed. The usual starting dose for adults is 200 mg once daily; your doctor may increase to 400 mg once daily if needed.
- For children over 2 years, dosing is based on body weight (3.3–6.6 mg/kg per day). Safety in children under 2 has not been established.
- Do not change the dose or stop treatment yourself.
- Regular blood tests to check your liver are mandatory before starting and during treatment; keep all scheduled appointments.
- Your doctor will reassess treatment if liver tests worsen or if response is inadequate.
Procedures and treatment changes
Tell the treating team before surgery, procedures, or any medicine change. Do not alter treatment without the responsible clinician. (1)
Missed dose
Contact your prescribing clinician or pharmacist for instructions.
Overdose
If an overdose is suspected, contact your local poison control centre or emergency services immediately.
Side effects
Oral ketoconazole carries a boxed warning for serious liver injury, and side effects can be severe. Common side effects include nausea, headache, diarrhea, abdominal pain, and abnormal liver function tests. Liver damage has occurred even without obvious risk factors, at various doses and durations.
Gastrointestinal upset
What to notice: Nausea, diarrhea, or abdominal pain.
What to do: Inform your clinician if these are persistent or bothersome. However, if nausea is accompanied by unusual tiredness or loss of appetite, seek medical assessment promptly because these may also be early signs of liver problems. (1)
Headache
What to notice: Headache occurring during treatment.
What to do: Mention to your clinician. (1)
Abnormal liver function tests
What to notice: Elevated ALT or AST detected on routine blood monitoring; you may not have symptoms initially.
What to do: This will be managed by your clinician. Your clinician will interrupt treatment if ALT rises above the upper limit of normal or increases by 30% or more from baseline. Attend all scheduled liver monitoring appointments. (1)
Possible liver injury
What to notice: Abnormal liver function tests are a supported adverse reaction, and serious hepatotoxicity is a boxed-warning risk.
What to do: Seek medical attention promptly for anything you are concerned about. The clinician will assess and decide whether treatment should be continued. (1)
Possible adrenal effects
What to notice: Doses of 400 mg/day or higher are known to decrease adrenocortical hormone secretion.
What to do: Contact your clinician for assessment. Adrenal function monitoring may be needed, particularly at doses of 400 mg/day or higher, or during prolonged stress. (1)
Serious warnings
Severe liver damage (hepatotoxicity) — emergency
Symptoms: Serious liver damage, which can be fatal, has occurred with both high-dose short-term and low-dose long-term use, including in patients with no obvious risk factors.
Action: Seek emergency medical attention for anything you are concerned about. Your clinician will assess and decide whether treatment should be continued. (1) (2)
Life‑threatening heart rhythm disturbance (QT prolongation/torsades de pointes) — emergency
Symptoms: This risk arises specifically from coadministration with the contraindicated QT-prolonging medicines listed above.
Action: Call emergency services immediately for anything you are concerned about. Inform paramedics and clinicians of all medicines taken. (1)
Adrenal effects at higher doses —
Symptoms: Doses of 400 mg/day or higher decrease adrenocortical hormone secretion, which is why adrenal function monitoring is recommended for at-risk patients.
Action: Contact your clinician promptly for anything you are concerned about; they will assess and advise. Adrenal function monitoring applies particularly at doses of 400 mg/day or higher, or during prolonged stress. (1)
Interactions
| Medicine or test | Effect | Action |
|---|---|---|
| QT‑prolonging drugs (dofetilide, quinidine, pimozide, cisapride, methadone, disopyramide, dronedarone, ranolazine) | Coadministration with ketoconazole can increase blood levels of these drugs and prolong the QT interval, risking life‑threatening ventricular arrhythmias. | This combination is contraindicated. Provide a full medication list to your prescriber and pharmacist so they can check for this. (1) |
| Ergot alkaloids, lovastatin, simvastatin | Not established from the sources reviewed: the specific mechanism/toxicity detail was not established in the sources reviewed for this page beyond this being a contraindicated combination. | This combination is contraindicated. Discuss appropriate alternatives with your prescriber. (1) |
| Oral midazolam, triazolam, alprazolam | Not established from the sources reviewed: the specific mechanism/toxicity detail was not established in the sources reviewed for this page beyond this being a contraindicated combination. | This combination is contraindicated. Other sedatives or anxiolytics may be used only under medical advice. (1) |
Pregnancy, breastfeeding, kidney/liver function, age
Children and adolescents
Ketoconazole has been used in children older than 2 years at weight‑based doses (3.3–6.6 mg/kg/day). Safety and effectiveness in children under 2 years have not been established. (1)
Pregnancy
Ketoconazole is classified as Pregnancy Category C. Animal studies have shown teratogenic effects. It should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus. Women who are pregnant or planning pregnancy must discuss this with their specialist. (1)
Breastfeeding
Information on ketoconazole excretion in human milk and effects on the breastfed infant is not available in the sources reviewed. Decisions about breastfeeding during treatment should be made jointly with a clinician, taking into account the importance of the drug to the mother and the unknown risks to the infant.
People with adrenal insufficiency or at risk for adrenal suppression
Ketoconazole at doses of 400 mg/day or higher reduces corticosteroid production. Patients with pre‑existing adrenal insufficiency, borderline adrenal function, or those undergoing prolonged stress (major surgery, intensive care) require adrenal function monitoring. (1)
People with liver disease
Ketoconazole is contraindicated in patients with acute or chronic liver disease because of the risk of severe hepatotoxicity. (1)
Monitoring
Before starting
- Confirm that the fungal infection is one of the approved indications (blastomycosis, coccidioidomycosis, histoplasmosis, chromomycosis, paracoccidioidomycosis) and that other effective antifungal therapies are not available or tolerated.
- Perform baseline liver function testing.
- Review all current medications for the specifically contraindicated combinations (see Interactions).
- Your clinician may also consider adrenal function and pregnancy status when starting treatment — the reviewed sources do not specify this as a formal mandatory checklist item.
During treatment
- Weekly serum ALT monitoring is required. Your clinician will interrupt treatment if ALT rises above the upper limit of normal or increases by 30% or more above the pre‑treatment value.
- For doses of 400 mg/day or more, adrenal function is monitored periodically, and particularly during periods of stress (surgery, acute illness).
Storage
Follow the directions on the product packaging and consult your pharmacist.
Professional information
Clinician‑facing context only. This page summarises US FDA‑approved labeling and a 2013 FDA safety communication. Prescribers must consult the current local product information and antifungal treatment guidelines.
United States
Indication: Systemic fungal infections (blastomycosis, coccidioidomycosis, histoplasmosis, chromomycosis, paracoccidioidomycosis)
Dose summary: Adult: 200 mg orally once daily; may increase to 400 mg once daily if response is inadequate. Children over 2 years: 3.3–6.6 mg/kg orally once daily. Not recommended for children under 2 years.
Renal context: The US label reports that in patients with hepatic or renal impairment the overall pharmacokinetics of ketoconazole were not significantly different from healthy subjects, and it gives no renal dose adjustment and no renal contraindication. Only about 13% of a dose is excreted in urine, of which 2 to 4% is unchanged drug. Hepatic function, not renal function, is the dominant safety consideration with this drug. (1)
Hepatic guidance
Ketoconazole is contraindicated in patients with acute or chronic liver disease. Baseline and weekly ALT monitoring is required. Treatment is interrupted (by the treating clinician) if ALT exceeds the upper limit of normal or rises by 30% or more above baseline. Hepatotoxic adverse events can be fatal and have occurred with both short‑term high‑dose and long‑term low‑dose therapy, even in patients with no pre‑existing risk factors.
Frequently asked questions
Why can't I use oral ketoconazole for a fungal nail infection or athlete's foot?
Because of the serious risk of liver injury and drug interactions, oral ketoconazole is no longer approved for skin, nail, or Candida infections. Ask your clinician what is appropriate for you. (2)
Are ketoconazole cream or shampoo safe? Do they have the same risks as the pill?
Topical ketoconazole products (applied to the skin or scalp) have not been associated with the liver damage, adrenal gland problems, or drug interactions seen with the oral tablets. They are considered to have a very different safety profile. Always check which form you are using. (2)
What are the warning symptoms of liver trouble I should watch for while taking oral ketoconazole?
Attend all scheduled liver-function blood tests, and seek medical attention promptly for anything you are concerned about — the clinician you see will determine whether to continue or stop treatment. (1)
What is the mechanism of action of ketoconazole?
References
- KETOCONAZOLE TABLETS USP, 200 mg Rx onlyU.S. National Library of Medicine (DailyMed) — FDA-approved labeling · United States · accessed 2026-08-05 · source 1
- FDA Drug Safety Communication: FDA limits usage of Nizoral (ketoconazole) oral tablets due to potentially fatal liver injury and risk of drug interactions and adrenal gland problems (July 2013) — secondary summaryU.S. Food and Drug Administration (summary via secondary search aggregation) · United States · dated 2013-07 · accessed 2026-08-05 · source 2
- Ketoconazole — patient drug information (MedlinePlus)U.S. National Library of Medicine (MedlinePlus) · US · accessed 2026-08-14 · source 3
- Ketoconazole — FDA approval record (Drugs@FDA ANDA218498)U.S. Food and Drug Administration · US · accessed 2026-08-14 · source 4
- ketoconazole — RxNorm normalized drug concept (RXCUI 6135)U.S. National Library of Medicine (RxNorm) · US · accessed 2026-08-14 · source 5
Brand names by country
Single-ingredient ketoconazole names are shown separately by country. Product availability, strengths, and supply rules can change; combination products are not included here.
Priority countries
United States
- Nizoral10 mg/mL, 1 g00mL · kramer laboratories
- Tagrit Antifungal Treament Ketoconazole 1%10 mg000g · tagrid llc
- Anti-Fungal1 mg00mL · shenzhen mengyue technology co., ltd.
- Anti Dandruff1 g00mL · guangzhou chuanma international trading co.,ltd.
- Gembooxt Ketoconazole 1% Medicated Shampoos.01 g/mL · guangdong quadrant ecological technology co., ltd.
- Cysndra Ketoconazole 1% Medicated Shampoos.01 g/mL · guangzhou xinhongda trading service co., ltd.
- iShanCare Balanitis Cleansing1 g00g · shenzhen ishan technology co., ltd
- Gemachlich ZuHause Ketoconazole 1% Anti-dandruff Shampoos.01 g/mL · guangzhou xinhongda trading service co., ltd.
- Ketodan20 mg/g · medimetriks pharmaceuticals, inc.
Canada
- NIZORAL -
- KETODERM