Diflucan vs. ketoconazole
- Diflucan (fluconazole) and ketoconazole are anti-fungal medications used to treat different types of fungal infections.
- Diflucan is used to treat vaginal, oral, and esophageal fungal infections caused by Candida; urinary tract infections, peritonitis, pneumonia and disseminated infections caused by Candida; cryptococcal meningitis; and to prevent Candida infections in patients treated with chemotherapy or radiation after bone marrow transplantation.
- Ketoconazole is used to treat thrush, ringworm, jock itch, athlete’s foot, dandruff, tinea versicolor, blastomycosis, histoplasmosis, and coccidiomycosis.
- Brand names of ketoconazole include Nizoral, Xolegel, and Extina.
- Side effects of Diflucan and ketoconazole that are similar include headache, nausea, abdominal pain, dizziness, and rash.
- Side effects of Diflucan that are different from ketoconazole include diarrhea, indigestion, low blood potassium (hypokalemia), and changes in taste.
- Side effects of ketoconazole that are different from Diflucan include itching, vomiting, fatigue, impotence, and blood count abnormalities.
What is Diflucan? What is ketoconazole?
Diflucan (fluconazole) is an anti-fungal medication related to clotrimazole (Lotrimin), ketoconazole (Nizoral), itraconazole (Sporanox), and miconazole (Micatin, Monistat). Diflucan prevents growth of fungi by preventing production of the membranes that surround fungal cells. Diflucan is used to treat vaginal, oral, and esophageal fungal infections caused by Candida; urinary tract infections, peritonitis, pneumonia and disseminated infections caused by Candida; cryptococcal meningitis; and to prevent Candida infections in patients treated with chemotherapy or radiation after bone marrow transplantation.
Ketoconazole is an anti-fungal medication used to treat fungal infections such as thrush, ringworm, jock itch, athlete’s foot, dandruff, tinea versicolor, blastomycosis, histoplasmosis, and coccidiomycosis. Ketoconazole prevents growth of several types of fungi by preventing production of the membranes that surround fungal cells. Ketoconazole is in the same drug class as fluconazole (Diflucan), itraconazole (Sporanox), and miconazole (Micatin, Monistat).
What are the side effects of Diflucan and ketoconazole?
Common side effects of fluconazole include
Other important side effects include
Possible serious side effects include
- reduced number of white blood cells,
- reduced number of blood platelets, and
- toxic epidermal necrolysis.
Rarely, serious allergic reactions, including angioedema (swelling of tissues), may also occur. Liver dysfunction (jaundice, hepatitis) and abnormal heart beats have been associated with fluconazole. Stevens-Johnson syndrome has also been reported.
Ketoconazole generally is well tolerated. Commonly reported side effects of ketoconazole are:
Other important side effects of ketoconazole are rare; they include:
Liver dysfunction also has been reported. Signs of liver problems include unusual fatigue, loss of appetite, nausea and vomiting, yellowing of the skin (jaundice), dark urine, and pale stools. Development of these symptoms while taking ketoconazole should be reported to a physician.
What is the dosage of Diflucan vs. ketoconazole?
- The usual adult dose is 50-400 mg daily depending on the type of infection. Although symptoms of oral Candida infections may subside in a few days, treatment is continued for 2 weeks.
- Esophageal Candida infections are treated for 3 weeks or longer.
- Treatment of cryptococcal meningitis may last for 10-12 weeks after cerebrospinal fluid cultures become negative.
- Ketoconazole may be taken with or without food. The oral dose range is 200-400 mg daily. Recurrent tinea versicolor is treated with 400 mg monthly. Topical formulations are administered to affected areas once or twice daily.
What drugs interact with Diflucan and ketoconazole?
- Hydrochlorothiazide increases the blood concentration of fluconazole by 40%. However, dosage modification is not recommended when both drugs are combined.
- Rifampin (Rifadin, Rimactane, Rifadin, Rifater, Rifamate) reduces the blood concentration of oral fluconazole, probably by increasing the elimination of fluconazole in the liver; therefore, reducing the effectiveness of fluconazole.
- Fluconazole may increase the concentration of warfarin (Coumadin, Jantoven) in blood by reducing the elimination of warfarin. Therefore, the effect of warfarin may increase, leading to an increased tendency to bleed.
- Fluconazole also increases the concentration of the following drugs in the blood, and as a result, the risk of side effects of these drugs may increase. These drugs include:
- phenytoin (Dilantin),
- zidovudine (Retrovir),
- saquinavir (Invirase),
- theophylline (Theo-Dur, Respbid, Slo-Bid, Theo-24, Theolair, Uniphyl, Slo-Phyllin),
- glyburide (Micronase, Diabeta, Glynase),
- triazolam (Glucotrol),
- midazolam (Versed),
- celecoxib (Celebrex),
- fentanyl (Sublimaze),
- atorvastatin (Lipitor),
- simvastatin (Zocor), and
- lovastatin (Mevacor).
- As a result, the risk of side effects from the above drugs may increase.
- Combining fluconazole with amiodarone (Cordarone), pimozide (Orap), bepridil (Vascor) or other drugs that affect heart rhythm may increase the risk of abnormal heart rhythms.
Systemic exposure to these drugs is increased by ketoconazole: Careful monitoring, with possible adjustment in dosage, is recommended.
(The above drug interaction section for ketoconazole is from FDA prescribing information)
Are Diflucan and ketoconazole safe to use while pregnant or breastfeeding?
- There are no adequate studies of Diflucan in pregnant women. There are reports of harmful effects to the fetus when high dose fluconazole was administered to pregnant women for a few months. Use of fluconazole during pregnancy is not recommended.
- Diflucan is secreted in breast milk at concentrations similar to the mother’s blood level. However, fluconazole is used for treating neonates with fungal infections and for treating lactation associated Candida infections. Available evidence suggests that use of fluconazole during breastfeeding has little risk.
- A small amount of ketoconazole is secreted in breast milk. Nursing mothers should probably avoid breastfeeding while using ketoconazole.
Infectious Disease Resources
Health Solutions From Our Sponsors
Medically Reviewed on 1/18/2019
FDA Prescribing Information