Fluconazole

What Is Fluconazole?

Fluconazole is a prescription antifungal medicine. It belongs to a group of medicines called triazole antifungals (often called “azole” antifungals). It is sold under the brand name Diflucan and as generic versions.

FDA-Approved Uses

Fluconazole is approved to treat certain fungal infections, mainly those caused by Candida (yeast) and Cryptococcus. These include:

• Vaginal yeast infections (vaginal candidiasis)
• Yeast infections of the mouth and throat (oropharyngeal candidiasis)
• Yeast infections of the esophagus (esophageal candidiasis)
• Candida infections of the urinary tract and abdominal cavity (peritonitis)
• Serious bloodstream or body-wide Candida infections
• Cryptococcal meningitis, a fungal infection of the tissues around the brain and spinal cord
• Prevention of Candida infections in people receiving a bone marrow transplant who are getting chemotherapy or radiation

Other Prescribed Uses

Doctors sometimes prescribe fluconazole for other fungal infections based on a patient’s individual situation. These decisions belong to the treating specialist.

Available Forms and Strengths

• Tablets: Fluconazole 50mg, Fluconazole 100mg, Fluconazole 150mg, Fluconazole 200mg, Fluconazole 400mg
• Oral suspension (liquid): commonly 10 mg/mL and 40 mg/mL
• Intravenous (IV) solution: given in a hospital or clinic for more serious infections

Available strengths can vary by manufacturer and country.

What Is the Recommended Dosage of Fluconazole?

There is no single dose that fits everyone. The prescribed dose and length of treatment depend on several factors:

• The condition being treated. Some infections are treated with a single dose. Others need treatment for weeks or months.
• Age. Children are usually dosed by body weight.
• Body weight.
• Kidney function. Fluconazole leaves the body mainly through the kidneys, so people with kidney problems may need a lower dose or less frequent dosing.
• Liver health and other medicines the person is taking.

Fluconazole comes as tablets, liquid, and IV solution. The form depends on the infection and on whether the person can swallow or absorb oral medicine.

Always take fluconazole exactly as your licensed medical specialist or pharmacist instructs. Do not change the dose, stop early, or extend treatment on your own, even if symptoms improve. Stopping too soon can allow some infections to return.

How Fluconazole Works

Fungal cells have a protective outer membrane. A substance called ergosterol is an important part of that membrane. Fluconazole blocks an enzyme fungi need to make ergosterol. Without enough ergosterol, the fungal cell membrane becomes weak and leaky, which slows or stops the fungus from growing.

Fluconazole treats or controls fungal infections, and it works mainly by stopping fungi from multiplying. This allows the body’s immune system to clear the infection. How well it works depends on the type of fungus, where the infection is, and the person’s overall health. It does not work against bacterial or viral infections.

Is a Prescription Required to Buy Fluconazole Online?

In the United States, fluconazole is a prescription-only medicine. A licensed healthcare professional must evaluate you before it is prescribed.

Depending on the infection, the specialist may be:

• A primary care physician
• A gynecologist (for vaginal infections)
• An infectious disease specialist (for serious or recurring infections)
• A dermatologist (for infections involving the skin, hair, or nails)

Only buy fluconazole from a licensed pharmacy that requires a valid prescription. Be careful with websites that sell it without one. Counterfeit, expired, or improperly stored products can be unsafe. Some products labeled fluconazole are made for animals (for example, pet or fish products). These are not approved for people and should never be used.

Side Effects of Fluconazole

Most people tolerate fluconazole well, but side effects can occur.

Common Side Effects

• Headache
• Nausea or upset stomach
• Stomach pain
• Diarrhea
• Dizziness
• Rash
• Changes in taste

These are often mild. Talk to your pharmacist or doctor if they bother you or do not go away.

Serious Side Effects

Serious reactions are uncommon but possible. Get medical help right away if you notice:

• Yellowing of the skin or eyes, dark urine, pale stools, or severe stomach pain (possible liver problems)
• Severe skin reactions, such as blistering, peeling, or sores in the mouth
• Swelling of the face, lips, tongue, or throat, or trouble breathing (allergic reaction)
• A fast, pounding, or irregular heartbeat, or fainting (possible heart rhythm changes)
• Seizures
• Extreme tiredness, weakness, low blood pressure, or vomiting that does not stop (possible adrenal gland problems)

Call emergency services if you have trouble breathing or think you are having a life-threatening reaction.

Drug Interactions

Fluconazole can change how the body processes many other medicines. This can raise the levels of some drugs in the blood and increase their side effects. Major categories include:

• Blood thinners (such as warfarin), which may increase bleeding risk
• Medicines that affect heart rhythm (certain antiarrhythmics, some antibiotics, and some antipsychotics)
• Cholesterol medicines (statins such as simvastatin and atorvastatin), which may raise the risk of muscle problems
• Diabetes medicines (sulfonylureas), which may cause low blood sugar
• Seizure medicines (such as phenytoin)
• Immune-suppressing medicines (such as cyclosporine, tacrolimus, and sirolimus)
• Sedatives and sleep medicines (such as certain benzodiazepines)
• Opioid pain medicines
• Blood pressure and heart medicines, including some calcium channel blockers and certain diuretics
• Rifampin, an antibiotic that can lower fluconazole levels
• Hormonal birth control

Tell your provider about all over-the-counter medicines (including pain relievers such as NSAIDs), vitamins, supplements, and herbal products. Also mention alcohol use.

Give your licensed medical specialist and pharmacist a complete, up-to-date list of everything you take. This list is not complete, so always check before starting or stopping any medicine.

Safety & Important Considerations

• Liver disease: Fluconazole can affect the liver. People with liver disease need careful monitoring, and liver blood tests may be done during longer treatment.
• Kidney disease: Doses may need to be adjusted.
• Heart conditions: Fluconazole can affect heart rhythm (QT prolongation). Extra caution applies to people with heart rhythm problems, low potassium or magnesium, or those taking other medicines with the same effect.
• Pregnancy: Studies have raised concerns about a possible increased risk of miscarriage, and high doses in early pregnancy have been linked to birth defects. The FDA has issued safety communications on this topic. Tell your provider if you are pregnant, may become pregnant, or are trying to conceive.
• Breastfeeding: Fluconazole passes into breast milk. Discuss the benefits and risks with your provider.
• Children: Fluconazole is used in children, with weight-based dosing determined by a specialist.
• Older adults: Kidney function often declines with age, so dose adjustment may be needed. Older adults also often take multiple medicines, which raises the chance of interactions.
• Alcohol: Ask your provider whether alcohol is safe, especially if you have liver concerns.

Who This Medication Is For

Fluconazole is prescribed for adults and children who have a confirmed or strongly suspected fungal infection that is sensitive to it, within its approved indications. It is also used to help prevent infection in certain high-risk patients, such as some bone marrow transplant recipients. Whether it is appropriate depends on the type of infection, medical history, other medicines, and test results.

Who Should Not Take Fluconazole

Fluconazole is not suitable for everyone. Do not take it if:

• You have had an allergic reaction to fluconazole. Tell your provider if you have reacted to other azole antifungals, since cross-reactions can occur.
• You take certain medicines that can cause dangerous heart rhythm problems when combined with fluconazole (for example, pimozide, quinidine, cisapride, or erythromycin). Your provider and pharmacist can check your list.

Use extra caution and discuss risks with your provider if you have:

• Liver or kidney disease
• A heart rhythm disorder or a family history of one
• Low potassium or magnesium levels
• A history of serious skin reactions to medicines
• Pregnancy, plans for pregnancy, or breastfeeding

What to Do If You Miss a Dose

• Take the missed dose as soon as you remember.
• If it is almost time for your next dose, skip the missed one and go back to your regular schedule.
• Do not take two doses at once to make up for a missed dose.
• If you are unsure what to do, or you are taking a single-dose or infrequent regimen, contact your licensed medical specialist or pharmacist.

Related medications to Fluconazole

Other antifungal medicines exist, and the right one depends on the type and location of the infection. Only a licensed specialist can decide whether a different medicine is appropriate.

Other azole antifungals (same class):

• Itraconazole
• Voriconazole
• Ketoconazole (oral use is limited because of liver risks)

Antifungals from other classes:

• Echinocandins (such as caspofungin and micafungin), usually given by IV
• Amphotericin B, usually given by IV for severe infections
• Terbinafine (an allylamine), used for some skin and nail infections
• Nystatin, used for some mouth and gut yeast infections

Topical or vaginal antifungals: clotrimazole, miconazole, and terconazole are available for some localized infections.

Do not switch or stop fluconazole without talking to your licensed medical specialist.

Storage Instructions

• Tablets: Store at room temperature, generally below 86°F (30°C), in the original container. Keep them dry and protected from moisture and light. Avoid storing them in a bathroom.
• Oral suspension: Keep at room temperature, tightly closed, and shake well before each use. Follow the pharmacy label for how long to keep it. Reconstituted liquid is usually discarded after about 14 days. Do not freeze.
• Child safety: Keep all medicines out of reach and sight of children and pets, preferably in a locked or high cabinet.
• Do not use medicine past its expiration date. Ask your pharmacist about safe disposal of unused or expired medicine.

Disclaimer:

This page is for educational purposes only. It is not a substitute for professional medical advice, diagnosis, or treatment. Patients must consult a licensed medical specialist, such as a primary care physician, gynecologist, infectious disease specialist, or dermatologist, depending on the type of infection, before starting, changing, or stopping treatment. Treatment decisions must be based on a full clinical evaluation by a qualified specialist. Information about dosing, strengths, and safety may change, so always follow the guidance of your prescriber and the current product labeling.