Fluconazole

Medically Reviewed by Dr. Harshi Dhingra, M.D.

Last Reviewed: Aug 01, 2022

Warnings


Fluconazole Risks, Warnings, and Complications


Fluconazole can cause serious health problems, especially in certain high-risk patients. Some of the risks of fluconazole use include:

  • LIVER DAMAGE: In a small number of people, fluconazole can lead to liver damage. This is usually reversible, and the liver heals when fluconazole is stopped. However, the damage can be severe enough to require a liver transplant in some people. The risk of suffering liver damage is higher in people with pre-existing liver disease, excessive alcohol use, or who take fluconazole for a long time. Contact your doctor immediately if you notice yellowing of your skin or eyes, dark urine, or stomach pain while on fluconazole. Your doctor may order blood tests to check liver function while you are on this antifungal medicine.

  • ALLERGIC REACTIONS: Rarely, fluconazole can lead to severe and potentially life-threatening allergic reactions, including anaphylaxis (closing the throat). Call 911 if this occurs. Contact your healthcare provider right away if you develop a severe skin reaction with hives and skin rash, swelling of the face, tongue, and lips, or difficulty breathing or swallowing while taking fluconazole.

  • EXFOLIATIVE DERMATITIS: Very rarely, fluconazole can cause a serious and potentially life-threatening skin reaction called exfoliative dermatitis. Signs and symptoms of this condition include itching and redness all over the body, skin pain, and scaling and peeling of the skin. Seek immediate medical help if you notice a severe rash, redness, blisters, and fever after taking fluconazole.

  • HARM TO AN UNBORN BABY: There is not much research available about the safety of fluconazole use during pregnancy, but some evidence says this medicine can lead to birth defects and miscarriage. Tell your doctor if you are pregnant, could be pregnant, or are planning a pregnancy before starting fluconazole. If you become pregnant while on fluconazole, stop taking the medicine and contact your doctor immediately.

If you are at a high risk of complications from fluconazole use, your doctor or pharmacist can help you find some other antifungal medicine for your condition that is safer for you.

Precautions Before Starting Fluconazole

Tell your doctor if you have ever had an allergic reaction to fluconazole, other antifungal medicines, any of the ingredients in fluconazole products, or any other medications. Your pharmacy can give you a list of ingredients 

Give your healthcare provider a complete medical history. Fluconazole may not be suitable for people with certain medical conditions such as cancer, AIDS, fast or pounding heartbeats, low levels of sodium, potassium, calcium, or magnesium in the blood, heart disease, kidney disease, liver disease, or a rare inherited condition where the body cannot tolerate lactose or sucrose.

Give your doctor a complete list of all your medications, including prescription drugs, over-the-counter medicines, vitamins, dietary supplements, and herbal products. This can help avoid serious interactions between fluconazole and other drugs.

Tell your doctor if you are pregnant, could be pregnant, plan to get pregnant, or are breastfeeding. Fluconazole can cause harm to the unborn baby, especially during the first 3 months of pregnancy. Your doctor may ask you to use birth control while you are on fluconazole and for one week after stopping this medicine to prevent pregnancy.

Precautions During Use of Fluconazole

Keep all your medical and lab appointments while on fluconazole. Your doctor may want to order certain medical tests while you are on this medication.

Tell your doctors you are taking fluconazole, especially before any surgery, including dental procedures.

Tell your doctor immediately if you become pregnant while on fluconazole.

Fluconazole can cause dizziness as a side effect. Do not drive or operate heavy machinery until you know how this medicine affects you.

Fluconazole Drug Interactions

Taking fluconazole with other concomitant medications can affect how each medication works. Interactions between medications can also increase the risk of serious side effects. Your physician may choose a different drug combination, change the dose or frequency of one or both medicines, and/or closely monitor you for side effects if there are known interactions between fluconazole and your other medications.

Your doctor will likely recommend not taking fluconazole if you are on the following medications:

  • Cisapride (Propulsid) (not available in the US) 
  • Terfenadine (Seldane) (not available in the US)
  • Astemizole (Hismanal) (not available in the US)
  • Erythromycin (E.E.S., E-Mycin, Erythrocin)
  • Quinidine (Quinidex)
  • Pimozide (Orap)

There can also be possible drug interactions between fluconazole and the following medications:

  • Antidepressants like amitriptyline and nortriptyline (Pamelor)
  • Antifugals like amphotericin B (AmBisome, Abelcet) and voriconazole (Vfend)
  • Anticoagulants or blood thinners like warfarin (Jantoven, Coumadin)
  • Blood pressure medication (calcium channel blockers) like amlodipine (Norvasc, Lotrel, Caduet), felodipine, nifedipine (Procardia, Afeditab, Adalat), and isradipine and angiotensin II receptor blockers like Losartan (Hyzaar, Cozaar)
  • Seizure medicine like carbamazepine (Carbatrol, Tegretol, Epitol, Equetro), phenytoin (Phenytek, Dilantin), and valproic acid (Depakote, Depakene)
  • NSAID pain relievers like Celebrex (celecoxib), Consensi (amlodipine/celecoxib)
  • Cholesterol medications such as atorvastatin (Lipitor), simvastatin (Zocor), fluvastatin (Lescol), and statin-containing products such as Caduet (atorvastatin/amlodipine) and Vytorin (ezetimibe/simvastatin).
  • Cancer medicine like cyclophosphamide, vinblastine, and vincristine (Marqibo)
  • Medicines used to prevent organ transplant rejection such as sirolimus (Rapamune), tacrolimus (Astagraf, Prograf), and cyclosporine (Neoral, Gengraf, Sandimmune)
  • Diuretics or water pills like hydrochlorothiazide (HCTZ) (Microzide), or HCTZ-containing products such as Diovan HCT (valsartan/HCTZ) and Tribenzor (olmesartan/amlodipine/HCTZ))
  • Opioid medications like fentanyl (Duragesic, Actiq, Fentora, Subsys, Sublimaze) and methadone (Methadose)
  • Tuberculosis medicines like isoniazid (Laniazid) or isoniazid-containing medications such as Rifater and Rifamate); rifampin (Rimactane, Rifadin), or rifampin-contaning products such as Rifamate (rifampin / isoniazid) and Rifater (rifampicin / isoniazid / pyrazinamide)
  • Other tuberculois medicines that used to prevent mycobacterium avium complex (MAC) disease in HIV patients such as rifabutin (Mycobutin)
  • Benzodiazepines like midazolam (Seizalam) and triazolam (Halcion)
  • Antiviral medicine for HIV like nevirapine (Viramune), zidovudine (Retrovir),or zidovudine-containing products such as Combivir (lamivudine / zidovudine),   Trizivir (abacavir / lamivudine / zidovudine), and saquinavir (Invirase)
  • Nonsteroidal anti-inflammatory drug (NSAID) such as ibuprofen (Motrin, Advil) and naproxen (Anaprox, Aleve, Naprelan)
  • Oral contraceptives (birth control pills)
  • Oral diabetes medicine like glyburide (Glynase, Diabeta), glipizide (Glucotrol), and tolbutamide
  • Steroid medicine like prednisone (Rayos)
  • Asthma medicine like theophylline (Theo-24, Elixophyllin, Theochron)
  • Rheumatoid arthritis medicine like tofacitinib (Xeljanz)
  • Vitamin A

This list does not describe all possible fluconazole drug interactions. Give your healthcare professionals a complete list of your medications, including prescription drugs, over-the-counter medicines, vitamins, dietary supplements, and herbal products. 

Tell your doctor and pharmacist if you have taken fluconazole in the last 7 days before starting any new medications. 

Also, tell your doctor if you smoke, drink alcohol, or use illegal drugs because some of these substances can cause serious health complications when used with prescription drugs.