A patient who has been hospitalized for 2 weeks has developed a pressure ulcer that contains multidrug-resistant Staphylococcus aureus (MRSA). Which drug would the nurse expect to be chosen for therapy?

Choice A reason: Itraconazole is a systemic antifungal used for infections like histoplasmosis. It inhibits ergosterol synthesis but is not typically used topically for athlete’s foot due to its oral or intravenous administration. Its systemic use carries risks like hepatotoxicity, making it unsuitable for localized dermatophyte infections.

Choice B reason: Ketoconazole is available as a topical cream but is less commonly used for athlete’s foot compared to terbinafine. It inhibits fungal ergosterol synthesis and is effective for cutaneous infections, but its topical use is more associated with seborrheic dermatitis or candidiasis, not primarily tinea pedis.

Choice C reason: Terbinafine is a topical antifungal commonly used for athlete’s foot (tinea pedis). It inhibits squalene epoxidase, disrupting fungal cell membrane synthesis, leading to fungal death. Its topical application effectively treats dermatophyte infections like Trichophyton, making it a first-line choice for localized fungal infections.

Choice D reason: Amphotericin B is a systemic antifungal used for severe fungal infections. It binds to ergosterol, causing fungal cell lysis, but is not used topically for athlete’s foot due to its toxicity and intravenous administration. It is reserved for life-threatening systemic infections, not cutaneous conditions.

Choice A reason: Garlic can enhance warfarin’s anticoagulant effect by inhibiting platelet aggregation and potentially increasing INR, raising bleeding risk. Its sulfur compounds may also induce hepatic enzymes, affecting warfarin metabolism. Patients on warfarin should avoid high garlic intake to maintain stable anticoagulation and prevent hemorrhage.

Choice B reason: Acetaminophen has no significant interaction with garlic. Acetaminophen is metabolized by the liver, primarily via glucuronidation, and garlic’s effects on platelet function or enzymes do not notably affect its pharmacokinetics or analgesic efficacy, making this an unlikely interaction concern.

Choice C reason: Phenytoin, an anticonvulsant, is metabolized by hepatic CYP450 enzymes, but garlic’s weak enzyme induction does not significantly alter phenytoin levels. Garlic’s primary interaction is with anticoagulants like warfarin, not anticonvulsants, making this drug less relevant for garlic-related concerns.

Choice D reason: Digoxin has no major interaction with garlic. Digoxin’s pharmacokinetics are primarily renal, and garlic’s effects on platelets or minor enzyme induction do not significantly alter digoxin levels or cardiac effects. Warfarin’s bleeding risk is more impacted by garlic’s antiplatelet properties.