Fluconazole (fluconazole)

Oral and IV dosage of fluconazole are identical.

Use of a fluconazole loading dose that is twice the daily dosage generally is recommended on the first day of treatment since this results in fluconazole plasma concentrations on the second day of treatment that are close to steady-state concentrations.

Dosage of the drug should be based on the type and severity of the infection, identity of the causative organism, and the patient's renal function and response to therapy. Fluconazole therapy should be continued until clinical parameters and/or laboratory tests indicate that active fungal infection has subsided; an inadequate period of treatment may lead to recurrence of active infection.

In patients with impaired renal function receiving multiple doses, fluconazole dosage must be modified in response to the degree of impairment and should be based on the patient's measured or estimated creatinine clearance. The patient's creatinine clearance (Clcr) can be estimated by using the following formula:

The manufacturer recommends that adults with impaired renal function receive an initial loading dose of 50-400 mg of fluconazole (based on the type of infection being treated), then patients with creatinine clearances exceeding 50 mL/minute should receive 100% of the usual daily dose and those with creatinine clearances of 50 mL/minute or less should receive 50% of the usual daily dose. Patients who are undergoing regular dialysis should receive 100% of the usual daily dose after each dialysis period; on days the patient is not receiving dialysis, reduced dosage based on creatinine clearance should be used. These dosage recommendations are based on the pharmacokinetics of the drug following multiple doses; further dosage adjustments may be necessary depending on the condition of the patient.

The manufacturer states that modification of the recommended single-dose regimen of oral fluconazole for the treatment of vulvovaginal candidiasis is not necessary in patients with impaired renal function.

The manufacturer states that the pharmacokinetics of fluconazole have not been studied in children with impaired renal function; recommendations for dosage reduction in such children should parallel those recommended for adults.

Fluconazole is administered orally or by IV infusion.

Since absorption of fluconazole from the GI tract is rapid and almost complete, IV therapy with the drug generally is reserved for patients who do not tolerate or are unable to take the drug orally.

No dosing information is available for this tab.

No dosing information is available for this tab.

While fluconazole can alter the pharmacokinetics of certain drugs that undergo hepatic metabolism, the magnitude of such alterations appears to be less than those associated with ketoconazole; however, comparative studies have not been performed to date. In addition, the possibility that the risk of developing such interactions may be increased at relatively high fluconazole dosages (e.g., 200 mg daily or more) should be considered.

There are no contraindication interactions for this drug.

There are no severe interactions for this drug.

There are no moderate interactions for this drug.

There is no enhanced messaging for this drug.

There are no contraindication contraindications for this drug.

There are no severe contraindications for this drug.

There are no moderate contraindications for this drug.

There is no enhanced messaging for this drug.

There are no severe adverse reactions for this drug.

There are no less severe adverse reactions for this drug.

No enhanced messaging available.

No enhanced messaging available.

FDA alerted clinicians in April 2016 that it is reviewing safety data regarding use of oral fluconazole during pregnancy and advised cautious prescribing of the drug until the review is completed.

There are no adequate and controlled studies to date using fluconazole in pregnant women.

Congenital abnormalities have been reported in infants born to women who received high-dose fluconazole (400-800 mg daily) for the treatment of serious, life-threatening fungal infections during most or all of the first trimester. These reports have involved a rare and distinct pattern of birth defects that includes brachycephaly, abnormal facies, abnormal calvarial development, cleft palate, femoral bowing, thin ribs and long bones, arthrogryposis, and congenital heart disease and are similar to those reported in animal reproduction studies. Based on these data, FDA reclassified high-dose fluconazole (400-800 mg daily) as pregnancy category D (i.e., there is positive evidence of human fetal risk based on human data, but potential benefits of the drug in pregnant women with serious or life-threatening conditions may be acceptable despite its risks).

Because human data available at that time did not identify an increased risk of congenital anomalies with the use of fluconazole administered as a single 150-mg oral dose for the treatment of vulvovaginal candidiasis, the single-dose oral fluconazole regimen was classified by FDA as pregnancy category C (see Users Guide). Data from a recent Danish study designed to assess the association between use of oral fluconazole during pregnancy and risk of spontaneous abortion and stillbirth indicate an increased risk of spontaneous abortion (i.e., miscarriage during gestational weeks 7 through 22) in pregnant women treated with oral fluconazole (most women received a total cumulative dose of 150-300 mg) compared with matched control pregnancies not exposed to oral fluconazole. Therefore, FDA alerted clinicians that it is reviewing data from the Danish study and additional data and, after completing the review, will communicate its conclusions and updated recommendations regarding use of the single-dose 150-mg oral fluconazole regimen during pregnancy.

The US Centers for Disease Control and Prevention (CDC) states that topical (intravaginal) azole antifungals (not oral fluconazole) should be used for the treatment of vulvovaginal candidiasis during pregnancy.

The Infectious Diseases Society of America (IDSA) states that use of fluconazole for the treatment of serious fungal infections (e.g., blastomycosis+, candidiasis, histoplasmosis+, coccidioidomycosis+, cryptococcosis) should be avoided during pregnancy.

Patients who are pregnant or actively trying to become pregnant should talk to their clinician about alternatives for treatment of vulvovaginal candidiasis.

If fluconazole is used during pregnancy or if the patient becomes pregnant while receiving the drug, the patient should be informed of the potential hazard to the fetus.

In several reproduction studies in pregnant rabbits receiving oral fluconazole dosages of 5, 10, 20, 25, or 75 mg/kg once daily during organogenesis, maternal weight gain was impaired at all dosage levels and abortions occurred with the 75-mg/kg dosage (approximately 20-60 times the usual human dosage); no adverse fetal effects were detected. In studies in pregnant rats receiving oral fluconazole during organogenesis, maternal weight gain was impaired and placental weights were increased at dosages of 25 mg/kg once daily. Although there were no fetal effects in rats receiving oral fluconazole in a dosage of 5 or 10 mg/kg once daily, increases in fetal anatomical variants (supernumerary ribs, renal pelvis dilation) and delays in ossification occurred in those receiving oral dosages of 25 mg/kg or greater once daily. When oral fluconazole dosages of 80 mg/kg once daily (approximately 20-60 times the usual human dosage) to 320 mg/kg once daily were used in these rats, there was an increase in embryolethality and fetal abnormalities (i.e., wavy ribs, cleft palate, abnormal craniofacial ossification). These adverse effects in rats may be attributed to a species-specific effect of fluconazole on estrogen synthesis since lowered estrogen is known to cause effects on pregnancy, organogenesis, and parturition. There is no evidence to date that estrogen concentrations are decreased in women receiving fluconazole. (See Cautions: Other Adverse Effects.)

Fluconazole is distributed into human milk in concentrations similar to those achieved in plasma. Administration of a single 150-mg oral dose to several nursing women resulted in peak plasma fluconazole concentrations of 2.61 mcg/mL (range: 1.57-3.65 mcg/mL). Fluconazole should be used with caution in nursing woman.

No enhanced messaging available.