Pharmacology: Ch. 42 Antifungal drugs

A patient is taking nystatin (Mycostatin) in an oral troche form for oral candidiasis. Which instruction is correct? A. Allow the troche to dissolve slowly in the mouth. B. Swish the medication in the mouth and then swallow it. C. Chew the troche thoroughly to activate the medication. D. Swallow the troche whole without chewing.

A. Allow the troche to dissolve slowly in the mouth.

A patient is diagnosed with onychomycosis. The nurse anticipates use of which medication for the treatment of this condition? A. terbinafine (Lamisil) B. voriconazole (Vfend) C. fluconazole (Diflucan) D. amphotericin B (Amphocin, Fungizone)

A. Terbinafine (Lamisil) is indicated for the treatment of onychomycosis (fungal infection of fingernail or toenail). --Voriconazole (Vfend) is indicated for the treatment of invasive aspergillosis and other major fungal infections in patients who do not tolerate or respond to other antifungal drugs. --Fluconazole (Diflucan) is indicated for the treatment of vaginal candidiasis, oropharyngeal and esophageal candidiasis, systemic candidiasis, and cryptococcal meningitis. --Amphotericin B (Amphocin, Fungizone) is indicated for the treatment of systemic infections with broad spectrum of fungi.

Flucytosine

Also known as 5-fluorocytosine (5-FC), (antimetabolite) Taken up by fungal cells and interferes with DNA synthesis Result: fungal cell death Older drug; newer drugs are more commonly used

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

Fifteen minutes after an infusion of amphotericin B was started, the patient begins to complain of fever, chills, muscle pain, and nausea. His heart rate has increased slightly, but his blood pressure is down to 100/68 mm Hg. What is the nurse's priority? A. Notify the prescriber immediately. B. Recognize an impending anaphylactic reaction and stop the infusion. C. Assess for other symptoms of this expected infusion-related reaction. D. Slow the infusion to reduce these adverse effects.

C. Assess for other symptoms of this expected infusion-related reaction.

Amphotericin B: Adverse effects

Cardiac dysrhythmias Neurotoxicity; tinnitus; visual disturbances; hand or feet numbness, tingling, or pain; convulsions Renal toxicity, potassium loss, hypomagnesemia Pulmonary infiltrates Fever, chills, headache, nausea, occasional hypotension, gastrointestinal (GI) upset, anemia

What are the four general types of mycotic infections?

Cutaneous Subcutaneous Superficial Systemic

A patient has developed an aspergillosis infection. Which tissue does the aspergillosis affect? A. Skin B. Nails C. Blood D. Lungs

D. Lungs

A patient is receiving amphotericin B lipid complex. The nurse knows that an advantage of the lipid formulations of this drug is that they: A. have a lower cost. B. can be administered quickly. C. take longer to be absorbed. D. cause fewer adverse effects.

D. cause fewer adverse effects.

Fungi that cause integumentary infections are known as _________.

Dermatophytes

Griseofulvin

Disrupts cell division Result: Inhibited fungal mitosis (cell division) Older drug; newer drugs are more commonly used

Adverse effects of fluconazole and nystatin

Fluconazole Nausea, vomiting, diarrhea, stomach pain, Increased liver enzymes Use with caution in patients with renal and liver dysfunction Nystatin Nausea, vomiting, anorexia, diarrhea, rash

The nurse has provided education to a client about fungal skin infections. Futher client teaching is necessary when the client includes which condition in the discussion of fungal skin infections? Thrush Impetigo Athlete's foot Vaginal yeast infection

Impetigo

Imidazoles and triazoles: ketoconazole, fluconazole, itraconazole, voriconazole

Inhibit fungal cell cytochrome P-450 enzymes, resulting in cell membrane leaking Result: altered cellular metabolism and fungal cell death

Antifungal drugs: Contraindications

Liver failure Renal failure Porphyria (griseofulvin) Drug allergy

Candida albicans

May follow 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

Molds

Multicellular Characterized by long, branching filaments called hyphae

What are fungul infections known as

Mycoses

Echinocandins: caspofungin, micafungin, and anidulafungin

Prevent the synthesis of glucans (essential components of fungal cell walls) Result: fungal cell death

Yeasts

Single-cell fungi Reproduce by budding Can be used for: -Baking -Alcoholic beverages

Drugs used to treat infections caused by fungi

Systemic --Amphotericin B, caspofungin, fluconazole, flucytosine, griseofulvin, itraconazole, ketoconazole, micafungin, nystatin, terbinafine, posaconazole, anidulafungin, and voriconazole. Topical Ophthalmic: natamycin

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 Fluconazole: passes into the cerebrospinal fluid and inhibit the growth of cryptococcal fungi, effective in the treatment of cryptococcal meningitis

True or False: Nystatin suspension should be swished thoroughly in the mouth as long as possible before swallowing

True

________ can cause fetal harm in pregnate women.

Voriconazole

Vaginal candidiasis

Yeast infection Pregnancy, women with diabetes mellitus, women taking oral contraceptives