BMA Concise Guide to Medicine & Drugs

Fluconazole

Brand names Azocan, Canestan Oral, Care Fluconazole, Diflucan

Used in the following combined preparations None

QUICK REFERENCE

Drug group Antifungal drug

Overdose danger rating Medium

Dependence rating Low

Prescription needed Yes (except for oral treatments for vaginal infections)

Available as generic Yes

GENERAL INFORMATION

Fluconazole is an antifungal drug that is used to treat local candida infections (“thrush”) affecting the vagina, mouth, and skin as well as systemic or more widespread candida infections. The drug is also used to treat some more unusual fungal infections, including cryptococcal meningitis. It may also be used to prevent fungal infections in patients with defective immunity. The dosage and length of course will depend on the condition being treated.

The drug is generally well tolerated, although side effects such as nausea and vomiting, diarrhoea, and abdominal discomfort are common.

INFORMATION FOR USERS

Your drug prescription is tailored for you. Do not alter dosage without checking with your doctor.

How taken/used Capsules, liquid, injection.

Frequency and timing of doses Once daily.

Adult dosage range 50–400mg daily.

Onset of effect Within a few hours, but full beneficial effects may take several days.

Duration of action Up to 24 hours.

Diet advice None.

Storage Keep in original container at room temperature out of the reach of children. Store liquid in a refrigerator (do not freeze) for no longer than 14 days.

Missed dose Take as soon as you remember. If your next dose is due within 6 hours, take a single dose now and skip the next.

Stopping the drug Take the full course. Even if you feel better, the original infection may still be present and may recur if treatment is stopped too soon.

Exceeding the dose An occasional unintentional extra dose is unlikely to be a cause for concern. But if you notice any unusual symptoms, or if a large overdose has been taken, notify your doctor.

POSSIBLE ADVERSE EFFECTS

Fluconazole is generally well tolerated. Most side effects affect the gastrointestinal tract and include nausea, vomiting, abdominal discomfort, diarrhoea, and flatulence. Rarely, a rash may occur; if so, you should stop taking the drug and consult your doctor.

INTERACTIONS

General note Interactions with other drugs relate to multiple doses of fluconazole. The relevance of a single dose is not established, but is likely to be small.

Rifampicin The effect of fluconazole may be reduced by rifampicin. Avoid using both drugs together.

Oral antidiabetic drugs Fluconazole may increase the risk of hypoglycaemia with sulphonylureas and other drugs such as nateglinide and repaglinide.

Anticoagulant drugs Fluconazole may increase the effect of oral anticoagulants such as warfarin.

Theophylline/aminophylline, midazolam, ciclosporin, tacrolimus, and zidovudine Fluconazole may increase the blood levels of these drugs.

Anti-epileptics Flucanazole may increase blood levels of phenytoin and carbamazepine.

Bosentan, ergotamine, methysergide, eletriptan, and ivabradine These drugs should not be used with flucanazole because of potentially dangerous interactions.

Oestrogens Contraceptive failure has occasionally been reported during treatment with fluconazole.

SPECIAL PRECAUTIONS

Be sure to tell your doctor if:

· You have long-term liver or kidney problems.

· You have previously had an allergic reaction to antifungal drugs.

· You have acute porphyria.

· You are taking other medicines.

Pregnancy May adversely affect the fetus if taken during pregnancy and should be avoided.

Breast-feeding The drug passes into the breast milk, although probably in amounts too small to be harmful. Discuss with your doctor.

Infants and children Reduced dose necessary.

Over 60 Normal dose used as long as kidney function is not impaired.

Driving and hazardous work No known problems.

Alcohol No known problems.

PROLONGED USE

Fluconazole is usually given for short courses of treatment. However, for prevention of relapse of cryptococcal meningitis in patients with defective immunity, it may be administered indefinitely.