How does this medication work? What will it do for me?

Fluconazole belongs to a group of medications known as antifungals. It is most commonly used to treat fungal infections of the mouth (thrush), esophagus (the tube that takes food from the throat to the stomach), lungs, urinary tract, and vagina (yeast infection). It works by preventing the fungi that are causing infection from reproducing and the infection from continuing. The fungi then die off, causing the infection to clear.

It is also used to treat cryptopcoccal meningitis and prevent the recurrence of cryptococcal meningitis in people with acquired immunodeficiency syndrome (AIDS), and to decrease the risk of candidiasis infection in people undergoing bone marrow transplants who are treated with chemotherapy or radiation therapy.

Your doctor may have suggested this medication for conditions other than those listed in these drug information articles. As well, some forms of this medication may not be used for all of the conditions discussed here. If you have not discussed this with your doctor or are not sure why you are taking this medication, speak to your doctor. Do not stop taking this medication without consulting your doctor.

Do not give this medication to anyone else, even if they have the same symptoms as you do. It can be harmful for people to take this medication if their doctor has not prescribed it.

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What form(s) does this medication come in?

50 mg
Each pink, rectangular, biconvex tablet with "G" on one side and "FL" over "50" on the other side, contains fluconazole 50 mg. Nonmedicinal ingredients: croscarmellose sodium, dibasic calcium phosphate anhydrous, FD&C Red No. 40 Aluminum Lake, magnesium stearate, microcrystalline cellulose, and povidone.

100 mg
Each pink, rectangular, biconvex tablet with "G" on one side and "FL" over "100" on the other side, contains fluconazole 100 mg. Nonmedicinal ingredients: croscarmellose sodium, dibasic calcium phosphate anhydrous, FD&C Red No. 40 Aluminum Lake, magnesium stearate, microcrystalline cellulose, and povidone.

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How should I use this medication?

To treat thrush (yeast infection of the mouth and throat), the recommended adult dose is 100 mg taken by mouth once daily for at least 2 weeks.

To treat esophageal candidiasis (yeast infection of the tube leading to the stomach), the recommended adult dose ranges from 100 mg to 200 mg taken daily for at least 3 weeks. Fluconazole must be taken for at least 2 weeks after the symptoms of the infection resolve to prevent the infection from returning.

To treat yeast infection that has spread throughout the body (disseminated yeast infection), the recommended adult dose of fluconazole is 200 mg to 400 mg once daily, for at least 4 weeks. Again, this medication must be taken for at least 2 weeks after the symptoms of the infection resolve to prevent the infection from returning.

To treat cryptococcal meningitis, the recommended dose of fluconazole is 200 mg to 400 mg once daily. Fluconazole should be taken for at least 10 weeks when treating this condition. To prevent cruptococcal meningitis, 200 mg taken once daily is recommended.

Childrens' doses are based on the child's body weight and will be calculated by the prescriber. A child's dose should not exceed 12 mg per kilogram of body weight.

Doses greater than 600 mg daily are not recommended for adults or children.

Many things can affect the dose of medication that a person needs, such as body weight, other medical conditions, and other medications. If your doctor has recommended a dose different from the ones listed here, do not change the way that you are taking the medication without consulting your doctor.

It is very important to take this medication on a regular schedule as prescribed by the doctor. Continue to take the full course of this medication even if you start to feel better. If you miss a dose of this medication, take it as soon as you remember it. If it is almost time for your next dose, skip the missed dose and continue with your regular schedule. Do not take a double dose to make up for a missed one. If you are not sure what to do after missing a dose, contact your doctor or pharmacist for advice.

Do not dispose of medications in wastewater (e.g. down the sink or in the toilet) or in household garbage. Ask your pharmacist how to dispose of medications that are no longer needed or have expired.

Who should NOT take this medication?

Fluconazole should not be taken by anyone who:

  • is allergic to fluconazole or to any of the ingredients of the medication
  • is taking the medication cisapride
  • is taking the medication terfenadine when fluconazole is taken in doses greater than 400 mg daily
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What side effects are possible with this medication?

Many medications can cause side effects. A side effect is an unwanted response to a medication when it is taken in normal doses. Side effects can be mild or severe, temporary or permanent. The side effects listed below are not experienced by everyone who takes this medication. If you are concerned about side effects, discuss the risks and benefits of this medication with your doctor.

The following side effects have been reported by at least 1% of people taking this medication. Many of these side effects can be managed, and some may go away on their own over time.

Contact your doctor if you experience these side effects and they are severe or bothersome. Your pharmacist may be able to advise you on managing side effects.

  • diarrhea
  • headache
  • nausea
  • skin rash
  • stomach pain
  • vomiting

Although most of these side effects listed below don't happen very often, they could lead to serious problems if you do not check with your doctor or seek medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

  • fever and chills
  • loss of appetite
  • signs of bleeding (e.g., bloody nose, blood in urine, coughing blood, cuts that don't stop bleeding)
  • signs of liver problems (e.g., nausea, vomiting, diarrhea, loss of appetite, weight loss, yellowing of the skin or whites of the eyes, dark urine, pale stools)
  • skin rash or itching

Stop taking the medication and seek immediate medical attention if any of the following occur:

  • seizures
  • signs of a severe allergic reaction (hives; difficulty breathing; swelling of the face, tongue, or throat)
  • symptoms of a severe skin rash (such as blistering, peeling, a rash covering a large area of the body, a rash that spreads quickly, or a rash combined with fever or discomfort)

Some people may experience side effects other than those listed. Check with your doctor if you notice any symptom that worries you while you are taking this medication.

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Are there any other precautions or warnings for this medication?

Before you begin using a medication, be sure to inform your doctor of any medical conditions or allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should use this medication.

Allergies: Caution should be used by those taking fluconazole who are allergic to other "azoles" such as ketoconazole or itraconazole. If you develop symptoms of an allergic reaction, such as skin rash, hives, difficulty breathing; swelling of the face, tongue, or throat, seek immediate medical attention.

Kidney function: People with kidney disease or reduced kidney function should discuss with their doctor how this medication may affect their medical condition, how their medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Liver damage: In rare cases, this medication may cause liver damage in people with serious medical conditions. Your doctor may monitor you with regular blood tests to check for side effects while you are taking fluconazole. If you notice signs of liver damage such as abdominal pain, yellowing of the skin or eyes, dark or amber urine, or pale stools, contact your doctor right away.

QT prolongation: In rare cases, this medication can affect the electrical activity of the heart and cause a condition known as QT prolongation. Your doctor will monitor your heart rhythm regularly while you are taking this medication with a test called an electrocardiogram (ECG). You should not take this medication if your ECG already shows that you have QT prolongation or if you are taking a medication that can cause QT prolongation.

Pregnancy: This medication should not be used during pregnancy unless the benefits outweigh the risks. If you become pregnant while taking this medication, contact your doctor immediately. Women who take fluconazole for vaginal yeast infections and who may become pregnant should consider using adequate birth control.

Breast-feeding: This medication passes into breast milk. If you are a breast-feeding mother and are taking fluconazole, it may affect your baby. Talk to your doctor about whether you should continue breast-feeding.

Children: This medication has been shown to be safe and effective for children over 6 months of age.

What other drugs could interact with this medication?

There may be an interaction between fluconazole and any of the following:

  • alfentanil
  • anti-HIV medications (e.g., atazanavir, indinavir, ritonavir, saquinavir)
  • astemizole
  • benzodiazepines (e.g., alprazolam, chlordiazepoxide, clonazepam, clorazepate, diazepam, flurazepam, midazolam)
  • birth control pills
  • buspirone
  • calcium channel blockers (e.g., amlodipine, diltiazem, nifedipine, nisoldipine, verapamil)
  • cimetidine
  • cisapride
  • clopidogrel
  • colchicines
  • cyclosporine
  • dapsone
  • diabetes medications (e.g., glyburide, tolbutamide)
  • didanosine
  • fosphenytoin
  • haloperidol
  • hydrochlorothiazide
  • ifosfamide
  • indapamide
  • irinotecan
  • losartan
  • macrolide antiobiotics (e.g., azithromycin, clarithromycin, erythromycin)
  • moclobemide
  • montelukast
  • paclitaxel
  • phenytoin
  • pimozide
  • procainamide
  • propafenone
  • quetiapine
  • quinidine
  • quinine
  • quinolone antibiotics (e.g., levofloxacin, norfloxacin, moxifloxacin)
  • rifabutin
  • rifampin
  • risperidone
  • sildenafil
  • sirolimus
  • SSRIs (e.g., fluoxetine, citalopram, escitalopram,
  • "statin" cholesterol medications (e.g., atorvastatin, lovastatin, simvastatin)
  • sulfonamide antibiotics (e.g., sulfadiazine, sulfamethoxazole)
  • tacrolimus
  • tadalafil
  • tamoxifen
  • temsirolimus
  • terfenadine
  • theophylline
  • thioridazine
  • tolterodine
  • tricyclic antidepressants (e.g., amitriptyline, desipramine, imipramine, nortriptyline)
  • vardenafil
  • vinblastine
  • vincristine
  • voriconazole
  • warfarin
  • zidovudine
  • zolpidem
  • zopiclone

If you are taking any of these medications, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:

  • stop taking one of the medications,
  • change one of the medications to another,
  • change how you are taking one or both of the medications, or
  • leave everything as is.

An interaction between two medications does not always mean that you must stop taking one of them. Speak to your doctor about how any drug interactions are being managed or should be managed.

Medications other than those listed above may interact with this medication. Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications that you are taking. Also tell them about any supplements you take. Since caffeine, decongestants, alcohol, the nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them.