Fluconazole, also known as Diflucan®, belongs to a general class of drugs known as antifungals. Other related drugs in this class include miconazole, itraconazole (Sporanox®) and ketoconazole (Nizoral®). Fluconazole is used in both dogs and cats to treat infections caused by fungi.
Fluconazole inhibits the growth of fungal organisms by interfering with the formation of the fungal cell wall.
Fluconazole is effective only against fungal or yeast organisms. These fungi are the ones that cause skin infections (dermatophytes) commonly known as “ringworm” and toenail infections. However, it also is effective for some more serious fungal infections, such as blastomycosis and cryptococcosis. These infections can affect the brain, bone and respiratory tract (lungs).
Fluconazole is a prescription drug and can only be obtained from a veterinarian or by prescription from a veterinarian.
This drug is not approved for use in animals by the Food and Drug Administration but it is prescribed legally by veterinarians as an extra-label drug.
Brand Names and Other Names Fluconazole
This drug is registered for use in humans only.
Human formulations: Diflucan® (Roerig)
Veterinary formulations: None
Uses of Fluconazole for Dogs and Cats
Fluconazole is used in both dogs and cats to treat infections caused by fungi. These infections may affect the skin, claws, brain, respiratory tract, bone and other tissues.
Fluconazole is not effective against infections caused by bacteria, parasites (intestinal worms), mites or viruses.
Precautions and Side Effects
While generally safe and effective when prescribed by a veterinarian, fluconazole can cause side effects in some animals.
Fluconazole should not be used in animals with known hypersensitivity or allergy to the drug.
Fluconazole may interact with other medications. Consult with your veterinarian to determine if other drugs your pet is receiving could interact with fluconazole. Such drugs include glipizide, cimetidine, amphotericin B, buspirone, corticosteroids, certain diuretics, fentanyl, losartan, quinidine, rifampin, theophylline, aminophylline, warfarin, cyclosporine and certain antibiotics.
The most serious adverse effect is that which affects the liver (hepatitis). Signs of decreased appetite, jaundice, vomiting or diarrhea should be reported to your veterinarian.
Compared to some of the other antifungal drugs (amphotericin B, ketoconazole), fluconazole has been associated with fewer adverse effects.
Fluconazole may cause vomiting, diarrhea and decreased appetite in dogs and cats.
How Fluconazole Is Supplied
Fluconazole is available in 50 mg, 100 mg, 150 mg or 200 mg tablets, or a 10 mg/ml to 40 mg/ml liquid oral suspension.
Also available as an injectable drug at 2 mg/mL.
Dosing Information of Fluconazole for Dogs and Cats
Medication should never be administered without first consulting your veterinarian.
The usual dose for dogs is 2.5 to 5 mg per pound (5 to 10 mg/kg) per day orally.
The dose for cats is 5 mg per pound (10 mg/kg) twice daily which often works out to be about 50 mg per cat twice daily orally.
It is common for fungal infections to require several weeks of treatment.
The duration of administration depends on the condition being treated, response to the medication and the development of any adverse effects. Be certain to complete the prescription unless specifically directed by your veterinarian. Even if your pet feels better, the entire treatment plan should be completed to prevent relapse or prevent the development of resistance.
