McKenna's Pharmacology for Nursing, 2e

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P A R T 2  Chemotherapeutic agents

Therapeutic actions and indications The topical antifungal drugs work to alter the cell per- meability of the fungus, causing prevention of replication and fungal death (see Figure 11.1). They are indicated only for local treatment of mycoses, including tinea infections. See Table 11.2 for usual indications. (See also Critical thinking scenario related to drug therapy.) Pharmacokinetics These drugs are not absorbed systemically and do not undergo metabolism or excretion in the body. Contraindications and cautions Because these drugs are not absorbed systemically, contraindications are limited to a known allergy to any of these drugs and open lesions. Econazole can cause intense, local burning and irritation and should be dis- continued if these conditions become severe. Terbinafine should not be used for longer than 4 weeks. This drug should be stopped when the fungal condition appears to be improved or if local irritation and pain become too great to avoid toxic effects. Adverse effects When these drugs are applied locally as a cream, lotion or spray, local effects include irritation, burning, rash and

swelling. When they are taken as a suppository or troche (lozenge), adverse effects include nausea, vomiting and hepatic dysfunction (related to absorption of some of the drug by the GI tract) or urinary frequency, burning and change in sexual activity (related to local absorption in the vagina). Prototype summary: Clotrimazole Indications: Treatment of oropharyngeal candidiasis (troche); prevention of oropharyngeal candidiasis in people receiving radiation or chemotherapy; local treatment of vulvovaginal candidiasis (vaginal preparations); topical treatment of tinea pedia, tinea cruris and tinea corporis. Actions: Binds to sterols in the fungal cell membrane, changing membrane permeability and allowing leakage of intracellular components, causing cell death. Pharmacokinetics: Not absorbed systemically; pharmacokinetics is unknown. Adverse effects: Troche: nausea, vomiting, abnormal liver function tests. Topical: stinging, redness, urticaria, oedema. Vaginal: lower abdominal pain, urinary frequency, burning or irritation in the sexual partner.

CRITICAL THINKING SCENARIO Poor nutrition and opportunistic infections

THE SITUATION P.P., a 19-year-old woman and aspiring model, complains of abdominal pain, difficulty swallowing and a very sore throat. The strict diets she has followed for long periods have sometimes amounted to a starvation regimen. In the last 18 months, she has received treatment for a variety of bacterial infections (e.g. pneumonia, cystitis) with a series of antibiotics. P.P. appears to be a very thin, extremely pale young woman who looks older than her stated age. Her mouth is moist, and small, white colonies that extend down the pharynx cover the mucosa. A vaginal examination reveals similar colonies. Cultures are performed, and it is determined that she has mucocutaneous candidiasis. Ketoconazole ( Nizoral ) is prescribed and P.P. is asked to return in 10 days for follow-up.

CRITICAL THINKING What are the effects of taking a variety of antibiotics on the normal flora? Think about the possible cause of the mycosis . What happens to the immune system and to the skin and mucous membranes when a person’s nutritional status becomes insufficient? How is P.P.’s chosen profession affecting her health? What are the possible ramifications of suggesting that P.P. change her profession or her lifestyle? What are the important nursing implications for P.P.? Think about how the nurse can work with P.P. to ensure some compliance with therapy and a return to a healthy state.