Until recently the treatment options for superficial
fungal infections have been limited mainly to the use of fungistatic drugs of the
imidazole class, discovered in the 1960s. The recent development of
allylamine and
benzylamine compounds provides
antifungal agents with fungicidal mechanisms of action. Both
imidazole and
allylamine/
benzylamine drugs interfere with the production of
ergosterol, an essential component of the fungal cell membrane; however, the newer drugs act at an earlier stage of the metabolic pathway than the
azoles and cause an accumulation of
squalene in the fungal cell, which leads to cell death. In vitro test results show that
allylamine/
benzylamine minimum inhibitory concentrations (MICs) and minimum fungicidal concentrations (MFCs) are lower than the MICs and MFCs of
azoles tested by the same methods. In studies using animal models of
dermatophytosis, results have shown the efficacy of the
allylamine/
benzylamine drugs to be superior to that of
azole drugs. Clinical trials have also shown significant differences favoring
allylamine/
benzylamine drugs over
imidazoles in the treatment of
dermatophytosis. The fungicidal drugs provide earlier evidence of efficacy, higher cure rates with shorter treatment periods, and lower relapse rates than
imidazoles in direct-comparison studies. The
allylamine/
benzylamine drugs have also shown high cure rates in patients with
candidiasis.