Fluconazole - Side Effects

What is fluconazole?

Fluconazole (generic drug) is a drug from the triazolenfamilie, which is used in the treatment of superficial and systemic infections of yeasts and fungi. It is available in tablet and oral suspension as well as infusion.

 which is used in the treatment of superficial and systemic infections of yeasts and fungi Fluconazole - Side Effects


Fluconazole inhibits the cytochrome P450 enzyme 14 demethylase of the fungus. The activity of the human variant of this demethylase enzyme is much less sensitive to fluconazole than the fungal variant. The inhibition of this enzyme prevents the conversion of lanosterol to ergosterol (provitamin D2), is an essential component of the cell membrane of the fungus, causing 14α-methyl sterols accumulate.

Fluconazole is primarily fungistatic, but may be fungicidal against some fungi, in a dose-dependent manner.

Fluconazole is active against the following microorganisms:
  • Blastomyces dermatitidis
  • Candida spp. (with the exception of C. krusei and C. glabrata)
  • Coccidioides immitis
  • Cryptococcus neoformans
  • Epidermophyton spp.
  • Histoplasma capsulatum
  • Microsporum spp.
  • Trichophyton spp.
After oral administration fluconazole is almost completely absorbed within two hours. Bioavailability is not significantly affected by concomitant ingestion of food or H2 blockers (eg, ranitidine). Concentrations measured in the urine, tears and skin are about 10 times the plasma concentration, whereas the concentrations in saliva, sputum and vaginal fluid are approximately the same as the plasma concentrations, after a (standard) dose of between 100 mg and 400 mg per day .

Fluconazole is only slowly excreted, it has a half-life of 20 to 50 hours and only 10% of the decrease is a result of metabolism, the rest is excreted in urine and perspiration. Patients with renal impairment have an increased risk of overdose, as well as patients who take medicines like warfarin. Fluconazole inhibits the enzyme CYP2C9.

In many cases, a 150 mg single dose may be sufficient, for example for leucorrhoea.

Clinical applications

Fluconazole is indicated for the treatment and prophylaxis of fungal infections when other antifungal medication is not tolerated, or does not start. (for example due to adverse events) including:
  • Candidiasis caused by this means susceptible strains of Candida. In the case of a light-Candida infection (thrush) is a single dose of 150 mg is often sufficient. The infection is severe, then a new dose required after three days.
  • Tinea corporis, tinea cruris or tinea pedis (athlete's foot)
  • Lime Nagel (onychomycosis)
Fluconazole may be the first choice for the following indications:
  • Coccidioidomycosis
  • Cryptococcosis, an opportunistic infection in AIDS, among others
  • Histoplasmosis,
  • Prophylaxis of candidiasis in the case of immunodeficiency.


Fluconazole therapy can give rise to extension of the (visible on an electrocardiogram) QT interval. This can lead to serious cardiac arrhythmia. Hence, caution should be exercised in patients with risk factors for prolongation of the QT interval, such as disturbance of the electrolyte balance or use of other medications that may prolong QT interval (especially cisapride, but also terfenadine).

Fluconazole-use is also associated in rare cases with severe and even fatal liver damage. Hence, regular liver function tests be performed during treatment with fluconazole. For this reason, caution should also be exercised in patients with pre-existing liver disease or hepatic impairment.

There may be other severe side-effects, such as Stevens-Johnson syndrome. However, that happens especially in people with AIDS who swallow several medicines simultaneously.

Fluconazole is contraindicated in patients with:
  • known hypersensitivity to fluconazole or other azole antifungals
  • concomitant use of cisapride and terfenadine, because of the risk of serious heart rhythm disturbances
  • pregnancy and lactation: High concentrations of fluconazole were found in the breast milk of women who used fluconazole. To use this reason, fluconazole is not recommended during breast-feeding.
Fluconazole side effects
Side effects that may be associated with the use of fluconazole:
  • Commonly (more than 1% of patients): rash, headache, dizziness, nausea, vomiting, abdominal pain, diarrhea, and / or elevated liver enzymes
  • Sporadic (0.1 - 1% of the patients): anorexia, fatigue, constipation
  • Rare (less than 0.1% of patients): oliguria, hypokalemia, dizziness, paraesthesia, seizures, alopecia, Stevens-Johnson syndrome, thrombocytopenia, severe hepatotoxicity, including liver failure, anaphylaxis
  • Very rare: prolongation of QT interval, torsades de pointes.
The following interactions are known:
  • In combination with anti-coagulants can fluconazole prolong the clotting time of the blood.
  • Flucozanol prolongs the half-life (time before the half of the substance out of the body has been removed) of co-administered sulfanylureumderivaten, so that there can be a low blood sugar.
  • Fluconazole may increase the blood levels of phenytoin, rifabutin, tacrolimus, cyclosporine, benzodiazepines and zidovudine. In combination with rifampicin it may be necessary to increase the dose flucozanol.

Fluconazole dosage

The dosage varies with indication and between patient groups, and can vary between a course of 150 mg daily for two weeks with vulvovaginal candidiasis to once per week between 150 and 300 mg for resistant skin infections. A daily dose of between 50 and 600 mg is sometimes used for systemic or severe infections and in a urgent infections such as meningitis caused by yeast can be used 800 mg / day.

Dosages for children are up to 8 mg / kg maximal.

Iklan Atas Artikel

Iklan Tengah Artikel 1

Iklan Tengah Artikel 2

Iklan Bawah Artikel