Antifungal
Antifungal
Antifungals bind to or impair sterols of fungal cell membranes, allowing increased permeability and leakage of cellular components and causing the death of the fungal cell.
Indications
Systemic fungal infections: Candidiasis, chronic mucocutaneous candidiasis, oral thrush, candiduria, blastomycosis, coccidioidomycosis, histoplasmosis, chromomycosis, paracoccidioidomycosis, dermatophytosis, ringworm infections of the skin Treatment of onychomycosis, pityriasis versicolor, vaginal candidiasis; topical treatment of tinea corporis and tinea cruris caused by Trichophyton rubrum, Trichophyton mentagrophytes, and Epidermophyton floccosum;treatment of tinea versicolor caused by Malassezia furfur (topical); and reduction of scaling due to dandruff (shampoo) Contraindications and cautions
Contraindicated with allergy to any antifungal, fungal meningitis, pregnancy, lactation. Use cautiously with hepatocellular failure (increased risk of hepatocellular necrosis). Adverse effects
CNS: Headache, dizziness, somnolence, photophobia GI: Hepatotoxicity,nausea, vomiting, abdominal pain GU: Impotence, oligospermia (with very high doses), nephrotoxicity Hematologic: Thrombocytopenia, leukopenia, hemolytic anemia Hypersensitivity: Urticaria to anaphylaxis Local: Severe irritation, pruritus, stinging with topical application Other: Pruritus, fever, chills, gynecomastia, electrolyte abnormalities (amphotericinB) Interactions
Drug-drug Decreased blood levels with rifampin Increased blood levels of cyclosporine and risk of toxicity with antifungals Increased duration of adrenal suppression when methylprednisolone, corticosteroids are taken with antifungals Nursing considerations
Assessment
History: Allergy to antifungals, fungal meningitis, hepatocellular failure, pregnancy, lactation Physical: Skin color, lesions; orientation, reflexes, affect; bowel sounds, liver evaluation, LFTs; CBC and differential; culture of area involved Interventions
Black box
warning Reserve systemic antifungals for patients with progressive and potentially fatal infections because of severe toxicity. Arrange for culture before beginning therapy; treatment should begin prior to lab results. Maintain epinephrine on standby in case of severe anaphylaxis after first dose. Administer oral drug with food to decrease GI upset. Administer until infection is eradicated: candidiasis, 1–2 wk; other systemic mycoses, 6mo; chronic mucocutaneous candidiasis often requires maintenance therapy; tinea versicolor, 2 wk of topical application. Discontinue treatment and consult physician about diagnosis if no improvement within 2 wk of topical application. Discontinue topical applications if sensitivity or chemical reaction occurs. Administer shampoo as follows: Moisten hair and scalp thoroughly with water; apply sufficient shampoo to produce a lather; gently massage for 1 min; rinse hair with warm water; repeat, leaving on hair for 3 min. Provide hygiene measures to control sources of infection or reinfection. Provide frequent small meals if GI upset occurs. Provide comfort measures appropriate to site of fungal infection. Arrange hepatic function tests prior to therapy and at least monthly during treatment. Establish safety precautions if CNS effects occur (side rails, assistance with ambulation). Teaching points
Take the full course of therapy. Long-term use of the drug will be needed; beneficial effects may not be seen for several weeks. Take oral drugs with meals to decrease GI upset. Apply topical drugs to affected area and surrounding area. Shampoo—moisten hair and scalp thoroughly with water; apply to produce a lather; gently massage for 1 minute; rinse with warm water; repeat, leaving on for 3 minutes. Shampoo twice a week for 4 weeks with at least 3 days between shampooing. Use hygiene measures to prevent reinfection or spread of infection. You may experience these side effects: Nausea, vomiting, diarrhea (take drug with food); sedation, dizziness, confusion (avoid driving or performing tasks that require alertness); stinging, irritation (local application). Report skin rash, severe nausea, vomiting, diarrhea, fever, sore throat, unusual bleeding or bruising, yellowing of skin or eyes, dark urine or pale stools, severe irritation (local applications). Representative drugs
amphotericin B anidulafungin butenafine butoconazole caspofungin ciclopirox clotrimazole econazole fluconazole flucytosine griseofulvin itraconazole ketoconazole micafungin miconazole naftifine nystatin 26 ? Antifungals Adverse effects
in italics are most common; those in bold are life-threatening. U Do not crush. oxiconazole posaconazole sertaconazole terbinafine tolnaftate voriconazole
