Ketoconazole
Also known as: Nizoral, Fungiconazole
- **Administration:** Give this medication with food to increase absorption and reduce stomach upset. If your pet develops vomiting or loss of appetite, dividing the daily dose may help. - **Side Effects:** Watch for loss of appetite, vomiting, or diarrhea. If these occur, contact your veterinarian. In cats, these side effects are more common. - **Coat Changes:** You might notice a reversible lightening of your pet's haircoat during treatment. - **Commitment:** Fungal infections often require months of continuous treatment. Do not stop the medication early even if your pet looks better, as the infection can easily return. - **Warning:** Inform your vet of *all* other medications your pet is taking, as ketoconazole interacts with many drugs.
Dosage must be set by your veterinarian for your specific pet. Never give human medication or another pet’s prescription without veterinary guidance.
What it is used for
- Coccidioidomycosis
- Coccidioidomycosis
- Blastomycosis
- Cryptococcosis
- Aspergillosis
- Dermatophytosis
- Sporotrichosis
- Susceptible yeasts and Aspergillus spp
- Scopulariopsis pneumonia
- Severe refractory candidiasis in Psittacines
- Susceptible fungal infections (most species)
- Susceptible fungal infections (most species)
- Susceptible fungal infections (Moluccan Cockatoos)
- Susceptible fungal infections (Ratites)
How it is given
Possible side effects
- Anorexia (most common, especially in cats)
- Vomiting
- Diarrhea
- Hepatic toxicity (cholangiohepatitis, increased liver enzymes)
- Thrombocytopenia (rare)
- Reversible lightening of haircoat
- Transient suppression of gonadal and adrenal steroid synthesis
- Infertility in male dogs (reversible)
- Hepatotoxicity
- Anorexia
- Alterations in hair-coat colour
- Thrombocytopenia (at high doses)
- Adrenal insufficiency (at high doses)
- Cataract development (in dogs)
Cautions & contraindications
- Known hypersensitivity to ketoconazole
- Controversial/Contraindicated in cats (due to toxicity risks)
- Concurrent use with cisapride or ivermectin (in dogs)
- Hepatic insufficiency
- Pregnancy (due to possible teratogenic effects)
- Use with caution in patients with **hepatic disease** or **thrombocytopenia**. Ketoconazole is a known **teratogen and embryotoxin**; weigh risks vs. benefits in pregnant animals. It may cause reversible infertility in male dogs by decreasing testosterone synthesis. Dogs undergoing high-dose antifungal therapy may need additional glucocorticoid support during periods of acute stress due to adrenal suppression.
Drug interactions
- Alcohol: May produce a disulfiram-like reaction (vomiting)
- Antacids: May reduce oral absorption of ketoconazole; administer at least 1 hour before or 2 hours after
- Tricyclic Antidepressants (amitriptyline, clomipramine): Ketoconazole may reduce metabolism and increase adverse effects
- Benzodiazepines (midazolam, triazolam): Ketoconazole may increase levels
- Buspirone: Plasma concentrations may be elevated
- Busulfan: Ketoconazole may increase levels
- Calcium-channel blockers (amlodipine, verapamil): Ketoconazole may increase levels
- Cisapride: Ketoconazole may increase cisapride levels and possibility for toxicity; use together contraindicated
- Corticosteroids: Ketoconazole may inhibit metabolism; potential for increased adverse effects
- Cyclophosphamide: Ketoconazole may inhibit metabolism; potential for increased toxicity
- Cyclosporine: Increased cyclosporine levels (often used therapeutically to reduce cyclosporine dose)
Frequently asked questions
What is Ketoconazole used for in pets?
- **Administration:** Give this medication with food to increase absorption and reduce stomach upset. If your pet develops vomiting or loss of appetite, dividing the daily dose may help. - **Side Effects:** Watch for loss of appetite, vomiting, or diarrhea. If these occur, contact your veterinarian. In cats, these side effects are more common. - **Coat Changes:** You might notice a reversible lightening of your pet's haircoat during treatment. - **Commitment:** Fungal infections often require months of continuous treatment. Do not stop the medication early even if your pet looks better, as the infection can easily return. - **Warning:** Inform your vet of *all* other medications your pet is taking, as ketoconazole interacts with many drugs.
Is Ketoconazole safe for my pet?
Dosage must be set by your veterinarian for your specific pet. Never give human medication or another pet’s prescription without veterinary guidance.
This article is for general education and is not a substitute for professional veterinary advice. If your pet is unwell, please consult a veterinarian.
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