Ketoconazole tablets should not be used as a first-line treatment for fungal infections because treatment has been associated with an increased risk of adrenal insufficiency, potentially fatal hepatotoxicity, and drug interactions, the Food and Drug Administration has announced.
Marketed as Nizoral, oral ketoconazole is no longer indicated for the treatment of Candida and dermatophyte infections and "should be used only for the treatment of certain life-threatening mycoses when the potential benefits outweigh the risks and alternative therapeutic options are not available or tolerated," according to the MedWatch safety alert issued on July 26.
In addition, oral ketoconazole should not be used to treat fungal infections of the skin and nails, and is only indicated for the treatment of blastomycosis, coccidioidomycosis, histoplasmosis, chromomycosis, and paracoccidioidomycosis "in patients in whom other treatments have failed or who are intolerant to other therapies," according to the label, which has been modified to reflect these risks and recommendations.
There is now a Medication Guide that will be provided to patients with each filled prescription of oral ketoconazole, explaining the risks.
Because oral ketoconazole has been associated with hepatoxicity that can result in liver transplantation or death, it is now contraindicated in patients with acute or chronic liver disease. The label also now recommends that patients be assessed and monitored for liver toxicity. Monitoring of adrenal function also is now recommended in patients who take the oral formulation of the drug and have adrenal problems or "are under prolonged periods of stress such as those who have had a recent major surgery or who are under intensive care in the hospital."
In addition, coadministration of ketoconazole – a potent inhibitor of the cytochrome P450 3A4 isoenzyme (CYP3A4) – with certain drugs is either restricted or contraindicated because of the increase in drug concentrations and increased risk of QT prolongation and other serious reactions. Contraindicated drugs include dofetilide, quinidine, pimozide, and cisapride.
The FDA changes are based on risk-benefit analyses of data that include reports made to the FDA’s Adverse Events Reporting System.
On July 26, the European Medicines Agency’s Committee on Medicinal Products for Human Use (CHMP) announced that it has concluded that the risk of hepatoxicity with oral ketoconazole products was greater than the benefits in treating fungal infections and recommended that these products no longer be marketed in the European Union.
Creams, shampoos, and other topical ketoconazole formulations have not been associated with these problems, according to the FDA.
The updated label is available here. Serious adverse events associated with ketoconazole should be reported to the FDA at 800-332-1088 or MedWatch.