Various anti-fungal drugs can be used for the treatment of cryptococcosis but most affected pets require prolonged therapy, often six months or more depending on the severity and extent of the disease. Treatments include: Ketoconazole. The response with ketoconazole is not as good as with some of the other anti-fungal drugs. Ketoconazole also may result in liver damage which may be identified by monitoring blood tests of liver function.
Itraconazole. The solution form of this drug appears to result in better absorption and availability to the tissues than does the capsule form. The adverse effects of itraconazole are similar to those of ketoconazole and include vomiting, diarrhea and liver damage.
Fluconazole has the advantage of providing excellent penetration into the brain and eyes (common sites of cryptococcal infection). Also, fluconazole has better availability to the tissues than does itraconazole. Also, fluconazole produces fewer adverse effects than does either ketoconazole or itraconazole. Fluconazole is not metabolized in the liver, and thus is safe in when there is concern about liver function. It is eliminated primarily by the kidneys, and its dosage should be adjusted if kidney failure is present.
Amphotericin B usually is by intravenous infusion after dilution in 5 percent dextrose in water. It must be given 3 times weekly until an effective cumulative dose has been reached. An alternative protocol involving subcutaneous administration of amphotericin B also has been developed. Amphotericin B is very toxic to the kidneys and kidney function must be monitored closely during treatment with amphotericin B.
Flucytosine is an anti-fungal drug that may be administered alone or in combination with amphotericin B. When used alone, the organism usually develops resistance to the drug.