Ketoconazole (Nizoral) Contraindications and Precautions
- breast-feeding
- ophthalmic administration
- achlorhydria
- alcoholism
- azole antifungals hypersensitivity
- children
- hepatic disease
- human immunodeficiency virus (HIV) infection
- hypochlorhydria
- ocular exposure
- onychomycosis
- pregnancy
Ketoconazole (Nizoral) Contraindications and Precautions
As with many other topical antifungal drugs, ketoconazole cream is not effective for onychomycosis. This condition usually requires treatment with an oral (systemic) antifungal drug.
Because oral ketoconazole requires an acidic environment for dissolution and absorption, patients with either achlorhydria or hypochlorhydria achieve poor plasma concentrations. These patients should take ketoconazole with dilute hydrochloric acid (0.1 or 0.2 N) to achieve better serum concentrations. Because hypochlorhydria has been reported in individuals with the human immunodeficiency virus (HIV) infection, the absorption of ketoconazole may be decreased in these patients.
Ketoconazole is metabolized in the liver and can be hepatotoxic, especially at higher doses. Hepatotoxicity appears primarily as a hepatocellular type of injury. Caution is advised in patients with a history of alcoholism or hepatic disease because these patients may have a baseline hepatocellular injury that can be exacerbated with ketoconazole usage.
No studies on ketoconazole have been performed in children under 2 years of age. Because of this, ketoconazole should be used with caution in children under 2 years.
Ketoconazole is classified as FDA pregnancy risk category C. Teratogenic effects have been demonstrated in animals using ketoconazole doses 10 times the maximum recommended human dose. Animal data are not always predictive of effects in humans. Birth defects have been reported in women who have taken fluconazole, another azole antifungal, for extended periods during pregnancy. The Guidelines for the Prevention of Opportunistic Infections in Patients with HIV recommend that oral azole antifungals, including ketoconazole, not be started during pregnancy and that these agents should be discontinued in HIV-positive women who become pregnant. Ketoconazole should be used in pregnant women only when the potential benefits to the mother outweigh the potential risks to the fetus. Women of childbearing potential should use effective contraception during ketoconazole therapy.
Ketoconazole is excreted in breast milk and can lead to kernicterus in the nursing infant. It is recommended that nursing mothers refrain from breast-feeding their infants during ketoconazole therapy and for 48 hours after therapy is completed.
Ketoconazole should be used with caution in patients with known azole antifungals hypersensitivity. Hypersensitivity reactions may be due to the various vehicles present in the different ketoconazole formulations. Ketoconazole may have a cross sensitivity with other azole derivatives such as itraconazole, fluconazole, clotrimazole, and miconazole. In rare cases, patients receiving ketoconazole have reported hypersensitivity reactions and even anaphylaxis. Ketoconazole is contraindicated in patients who have previously demonstrated these reactions.
Avoid accidental ocular exposure. If ocular exposure occurs, treat by immediate flushing the affected eye with cool, clean water; do not administer via ophthalmic administration. Contact an ophthalmologist if eye irritation persists.
[ Last revised: 10/21/2003 4:09:00 PM ]
References
. Centers for Disease Control and Prevention (CDC). The Living Document: USPHS/IDSA Guidelines for the prevention of opportunistic infections in persons infected with human immunodeficiency virus. Retrieved November 28, 2001.
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