Pharmacy Author: Omudhome Ogbru, PharmD
Medical and Pharmacy Editor: Jay W. Marks, MD

GENERIC NAME: fluconazole

BRAND NAME: Diflucan

DRUG CLASS AND MECHANISM: Fluconazole is an anti-fungal medication related to clotrimazole (Lotrimin), ketoconazole (Nizoral), itraconazole (Sporanox), and miconazole (Micatin, Monistat). It prevents growth of fungi by preventing production of the membranes that surround fungal cells. The Food and Drug Administration approved fluconazole in January 1990.

PRESCRIPTION: yes

GENERIC AVAILABLE: yes

PREPARATIONS: Tablets: 50, 100, 150, 200 mg. Oral Suspension: 10 mg/ml and 40 mg/ml. Injection: 2 mg/ml

STORAGE: Store tablets and dry powder below 86 F (30 C). Store injection and reconstituted suspension between 5-30 C (41-86 F). Discard unused portion of the reconstituted suspension after 2 weeks. Protect from freezing.

PRESCRIBED FOR: Fluconazole is used for treating vaginal, oral, and esophageal fungal infections caused by Candida. It may also be effective in treating urinary tract infections, peritonitis, pneumonia and disseminated infections caused by Candida. Fluconazole is also used for treating cryptococcal meningitis, and prevention of Candida infections in patients treated with chemotherapy or radiation after bone marrow transplantation.

DOSING: The usual adult dose is 50-400 mg daily depending on the type of infection. Although symptoms of oral candida infections may subside in a few days treatment is continued for 2 weeks. Esophageal Candida infections are treated for 3 weeks or longer. Treatment of cryptococcal meningitis may last for 10-12 weeks after cerebrospinal fluid cultures become negative.

DRUG INTERACTIONS: Hydrochlorothiazide significantly increases the blood concentration of oral fluconazole by reducing the elimination of fluconazole by the kidneys. This interaction may increase the side effects of fluconazole. Rifampin (Rifadin, Rimactane, Rifadin, Rifater, Rifamate) reduces the blood concentration of oral fluconazole, probably by reducing the metabolism of fluconazole in the liver; therefore, reducing the effectiveness of fluconazole. Fluconazole may increase the concentration of warfarin (Coumadin) in blood by reducing the metabolism of warfarin. Therefore, the effect of warfarin may increase, leading to increased tendency to bleed. Fluconazole also increases the concentration of phenytoin (Dilantin), cyclosporine, zidovudine (Retrovir), theophylline (Theo-Dur, Respbid, Slo-Bid, Theo-24, Theolair, Uniphyl, Slo-Phyllin), tolbutamide, glyburide (Micronase, Diabeta, Glynase), glipizide, triazolam (Glucotrol), and midazolam (Versed).

PREGNANCY: There are no adequate studies in pregnant women. There are reports of harmful effects to the fetus when high dose fluconazole was administered to pregnant women for a few months. Use of fluconazole during pregnancy is not usually recommended.

NURSING MOTHERS: Fluconazole is secreted in breast milk. Use of fluconazole by nursing mothers is not recommended.

SIDE EFFECTS: Common side effects include headache, nausea, and abdominal pain. Other side effects included diarrhea, dyspepsia, dizziness, rash, and taste disturbance. Rarely, serious allergic reactions, including angioedema (swelling of tissues), may also occur. Liver dysfunction (jaundice, hepatitis) has also been associated with fluconazole.

Reference: FDA Prescribing Information