McKenna's Pharmacology for Nursing, 2e

157

C H A P T E R 1 1  Antifungal agents

TOPICAL ANTIFUNGALS Some antifungal drugs are available only in topical forms for treating a variety of mycoses of the skin and mucous membranes. Some of the systemic antifungals are also available in topical forms. Fungi that cause these mycoses are called dermatophytes. These diseases include a variety of tinea infections, which are often referred to as ringworm, although the causal organism is a fungus, not a worm. These mycoses include tinea infections such as athlete’s foot (tinea pedis), jock itch (tinea cruris) and yeast infections of the mouth and vagina often caused by Candida. Because the antifungal drugs reserved for use as topical agents are often too toxic for systemic administration, care is necessary when using them near open or draining wounds that might permit systemic absorption. Topical antifungals include the azole-type antifungals—butoconazole ( Gynazole ), clotrimazole ( Canesten , Clonea ), econazole ( Pevaryl ), ketoconazole ( Nizoral ), miconazole ( Daktarin , Resolve ) and terbinafine ( Lamisil )—and other antifungals— ciclopirox ( Stieprox ), gentian violet (generic), tolnaftate ( Mycil , Tinaderm , Tineafax ) and undecenoic acid ( Gordochom ). (See Table 11.2.)

■ ■ Evaluate the effectiveness of the teaching plan (person can name the drug, dosage, possible adverse effects to watch for and specific measures to help avoid adverse effects). ■ ■ Monitor the effectiveness of comfort and safety measures and compliance with the regimen.

KEY POINTS

■■ Fungi can cause many different infections in humans. ■■ Fungi differ from bacteria in that a fungus has a rigid cell wall that is made up of chitin and various polysaccharides and a cell membrane that contains ergosterol. ■■ Systemic antifungal drugs can be very toxic; extreme care should be taken to ensure that the right drug is used to treat an infection and that the person is monitored closely to prevent severe toxicity. ■■ Systemic antifungals are associated with many drug–drug interactions because of their effects on the liver. Monitor a person closely when adding or removing a drug from a drug regimen if the person is receiving a systemic antifungal.

TABLE 11.2

DRUGS IN FOCUS Topical antifungals

Drug name

Dosage/route

Usual indications

Azole topical antifungals butoconazole (Gynazole)

Vaginal cream; applied only once a day for 4 weeks Available OTC as a cream, lotion, or solution; applied as a thin layer twice a day for 2–4 weeks Applied to affected wet body on three consecutive evenings Available in cream, gel, foam, and shampoo form; applied once to twice daily for 2–4 weeks Available as an OTC product in several topical forms (vaginal suppository, cream, powder, solution, ointment, gel and spray); applied twice daily for 2–4 weeks

Available over-the-counter (OTC) for treatment of vaginal Candida infections Available OTC for treatment of oral and vaginal Candida infections; tinea infections Treatment of tinea, candidiasis of skin or external genitalia Treatment of seborrhoeic dermatitis, tinea corporis, tinea cruris, tinea pedis

clotrimazole (Canesten, Clonea)

econazole (Pevaryl)

ketoconazole (DaktaGOLD Nizoral, Sebizole)

miconazole (Daktarin, Resolve)

Treatment of local, topical mycoses, including bladder and vaginal infections and athlete’s foot

terbinafine (Lamisil)

Available as a cream or gel; used for 1–4 weeks; applied twice daily

Short-term (1–4 weeks) treatment of topical mycosis; treatment of tinea infections

Other topical antifungals ciclopirox (Stieprox)

Available as a liquid for use as a shampoo

Treatment of dandruff, seborrhoeic dermatitis Available OTC for treatment of athlete’s foot, topical fungal infections, tinea Treatment of onychomycosis, cutaneous fungal infections

tolnaftate (Mycil, Tinaderm, Tineafax)

Available as a cream, solution, gel, powder, and spray; applied twice a day for 2–4 weeks

undecenoic acid (Gordochom)

Available as a solution