Ketoconazole
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Ketoconazole is a synthetic antifungal drug used to prevent and treat skin and fungal infections, especially in immunocompromised patients such as those with AIDS. Due to its side-effect profile, it has been superseded by newer antifungals, such as Fluconazole and Itraconazole. It is sold commercially as Nizoral by Janssen Pharmaceutica.
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History
Ketoconazole was discovered in 1976 and released in the early 1980s, and was the first available oral treatment of fungal infections.
Usage
Ketoconazole is usually prescribed for infections such as athlete's foot, ringworm, candidiasis (yeast infection or thrush), jock itch.
The sides-effects of Ketoconazokle sometimes used to treat non-fungal problems. The decrease in testosterone caused by the drug makes it useful for treating prostate cancer. Another use is the suppression of glucocorticoid synthesis, where it is used in the treatment of Cushing's disease. These side effects have also been studied for use in reducing depressive symptoms and drug addiction, however it has not succeded in either of these roles.
Ketoconazole can be prescribed as a 200 mg pill, a 2% ointment, or 2% shampoo for the treatment of dandruff or seborrhoeic dermatitis.
It is a Pregnancy category C drug because animal testing has shown it to cause Teratogenesis in high dosages. Only two human test cases have been recorded (both during the treatment of Cushing's disease) and no adverse effects were reported, however this is not a broad enough data sample to draw conclusions from.
Method of action
Ketoconazole is best absorbed at highly acidic levels, so antacids or other causes of decreased stomach acid levels will lower the drug's effectiveness when taken orally.
Ketoconazole is imidazole structured, and interferes with the fungal synthesis of ergosterol, the main constituent of cell membranes, as well as certain enzymes. It is specific for fungi, as mammalian cell membranes contain no ergosterol.
Sensitive fungi
Ketoconazole inhibits growth of dermatophytes and yeast species (such as Candida albicans). No resistance has been reported.
