Terbinafine is the
drug of choice for dermatophyte
onychomycosis. Adjunct
therapies, such as topical agents or surgical approaches, may improve outcomes in patients who have risk factors for incomplete response or recurrence. Despite many studies of newer
antifungal agents for
tinea capitis,
griseofulvin (20 mg/kg/d) remains the gold standard.
Terbinafine (> or = 6 mg/kg/d) and
fluconazole (8 mg/kg once weekly) have yet to demonstrate comparable efficacy in large-scale RCTs. The current role of second-generation
triazoles and
echinocandins is for treatment of
invasive candidiasis and invasive
aspergillosis in patients who are
critically ill and immunocompromised. Strengths of the newer
triazoles include increased activity against resistant and emerging pathogens, convenience of oral formulations, and in vivo activity against subcutaneous
mycoses, in particular eumycotic
mycetoma. Their metabolism via
cytochrome P450 isoenzymes increases the risk for significant drug interactions, and their established mechanism of action may lead to development of resistant pathogens. The
echinocandins inhibit fungal cell wall synthesis, a novel therapeutic target; thus, they are effective against
azole-resistant species. Their metabolism is independent of hepatic
cytochrome P450 enzymes, minimizing drug interactions. They are available only as i.v. formulations.