ANTIFUNGAL DRUGS ANTIFUNGAL DRUGS Drugs used to treat

ANTIFUNGAL DRUGS

ANTIFUNGAL DRUGS Drugs used to treat infections caused by fungi Systemic Topical

ANTIFUNGAL DRUGS FUNGI Very large and diverse group of microorganisms Broken down into yeasts and molds Fungal infections also known as mycoses Some fungi are part of the normal flora of the skin, mouth, intestines, vagina Reproduce by budding Can be used for Baking Alcoholic beverages

ANTIFUNGAL DRUGS YEASTS Multicellular Characterized by long, branching filaments called hyphae

ANTIFUNGAL DRUGS MYCOTIC INFECTIONS Four general types Cutaneous Subcutaneous Superficial Systemic* *Can be life threatening *Usually occur in immunocompromised host

ANTIFUNGAL DRUGS MYCOTIC INFECTIONS Candida albicans Due to antibiotic therapy, antineoplastics, or immunosuppressants (corticosteroids) May result in overgrowth and systemic infections Growth in the mouth is called thrush or oral candidiasis Common in newborn infants and immunocompromised patients Vaginal candidiasis “Yeast infection” Pregnancy, women with diabetes mellitus, women taking oral contraceptives

ANTIFUNGAL DRUGS Systemic amphotericin B, caspofungin, fluconazole, ketoconazole, others Topical Examples: clotrimazole, miconazole, nystatin Major groups based on their mechanisms of action Polyenes: amphotericin B and nystatin Imidazoles: ketoconazole (Nizoral) Triazoles: fluconazole (Diflucan), itraconazole (Sporanox) Echinocandins: caspofungin (Cancidas), micafungin Listed individually, not by mechanism of action: griseofulvin, flucytosine

ANTIFUNGAL DRUGS MECHANISM OF ACTION Polyenes: amphotericin B and nystatin Bind to sterols in cell membrane lining Result: fungal cell death Do not bind to human cell membranes or kill human cells Use: Serious systemic fungal infections Administered: IV, PO, topical

ANTIFUNGAL DRUGS MECHANISM OF ACTION Flucytosine (Ancobon) Also known as 5 -fluorocytosine (antimetabolite) Taken up by fungal cells and interferes with DNA synthesis Result: fungal cell death Use: Systemic mycoses due to Candida species or Cryptococcus neoformans – administered orally

ANTIFUNGAL DRUGS MECHANISM OF ACTION Imidazoles and triazoles: Ketoconazole (Nizoral), fluconazole (Diflucan) Inhibit fungal cell cytochrome P-450 enzymes, resulting in cell membrane leaking Lead to altered cell membrane Result: fungal cell death Use: Ketoconazol (Nizoral): (po/topical): candidiasis, histoplasmosis, coccidoidomycosis; cutaneous candidiasis; tinea infections Use: fluconazole (Diflucan): (po/IV): systemic, oral, esophageal or vaginal candidiasis; prevention of candidiasis after bone marrow transplant; cryptococcal meningitis.

ANTIFUNGAL DRUGS MECHANISM OF ACTION griseofulvin Disrupts cell division Result: inhibited fungal mitosis (reproduction) Use: (po) Dermatophytosis (skin, hair, nails)

ANTIFUNGAL DRUGS MECHANISM OF ACTION Echinocandins: capsofungin (Cancidas) Prevent the synthesis of glucans, which are essential components of fungal cell walls Causes fungal cell death Use: (IV) Invasive aspergillosis, Candidiasis

ANTIFUNGAL DRUGS INDICATIONS Systemic and topical fungal infections Drug of choice for the treatment of many severe systemic fungal infections is amphotericin B Choice of drug depends on type and location of infection

ANTIFUNGAL DRUGS ADVERSE EFFECTS – AMPHOTERICIN B Fever / Headache Chills Dysrhythmias Malaise Nausea Hypotension Anorexia Muscle and joint pain Lowered potassium and magnesium levels Main concerns: *Renal toxicity *Neurotoxicity: seizures and paresthesias Many other adverse effects

ANTIFUNGAL DRUGS ADVERSE EFFECTS Fluconazole (Diflucan) Nausea, vomiting, diarrhea, stomach pain, increased liver function studies Flucytosine (Ancobon) Nausea, vomiting, anorexia, headache, dizziness, others griseofulvin Rash, urticaria, headache, nausea, vomiting, anorexia, others

ANTIFUNGAL DRUGS CONTRAINDICATIONS Liver failure Renal failure Porphyria: genetic disorder-erythrocyte formation/liver dysfunction (griseofulvin)

ANTIFUNGAL DRUGS INTERACTIONS Many antifungal drugs are metabolized by the cytochrome P-450 enzyme system Co administration of two drugs that are metabolized by this system may result in competition for these enzymes, and thus higher levels of one of the drugs

ANTIFUNGAL DRUGS NURSING IMPLICATIONS Before beginning therapy, assess for hypersensitivity, contraindications, and conditions that require cautious use Obtain baseline VS, CBC, liver and renal function studies, and EKG Assess for other medications used (prescribed and OTC) in order to avoid drug interactions Follow manufacturer’s directions reconstitution and administration Monitor VS of patients receiving IV infusions every 15 to 30 minutes During IV infusions, monitor I&O to identify adverse effects

ANTIFUNGAL DRUGS NURSING IMPLICATIONS amphotericin B To reduce the severity of the infusion-related reactions, pretreatment with an antipyretic (acetaminophen), antihistamines, antiemetics, and corticosteroid may be given Use IV infusion pumps and the most distal veins possible Some oral forms should be given with meals to decrease GI upset; others require an empty stomach—be sure to check

ANTIFUNGAL DRUGS NURSING IMPLICATIONS Nystatin given as an oral lozenge should be slowly and completely dissolved in the mouth (not chewed or swallowed whole) Nystatin suspension should be swished thoroughly in the mouth as long as possible before swallowing Monitor for therapeutic effects Easing of the symptoms of infection Improved energy levels Normal vital signs, including temperature Monitor carefully for adverse effects