As an antifungal agent, terbinafine offers a number of benefits for the treatment of fungal infections of the skin and nails, as described by DT Roberts in the journal Dermatology. Adimi et al demonstrated terbinafine's potency in treating a number of different fungal strains in a study published in 2013.
Terbinafine acts on dermaphytes, which are fungal strains that require keratin for growth – keratin is found in the hair, skin and nails. Roberts describes terbinafine's potential effectiveness in short-term treatment durations due to the 1:1 ratio of the minimal inhibitory concentration (MIC) to the minimal fungicidal concentration (MFC), which is the relationship by which antifungal agents are measured. Roberts also notes that therapeutic concentrations of the drug remain in a patient's system after treatment is stopped; one of the reasons terbinafine is effective even when it is only administered in short durations.
In their 2013 paper, Adimi et al cite an overall treatment failure of antifungal agents in 25 to 40 percent of patients with onychomycosis (nail fungus) and 6.5 percent of those with tinea corporis (ringworm) and tinea cruris (fungal infection of the genitals, inner thighs and buttocks). For this reason, the study's authors tested terbinafine and nine other antifungal agents against 320 dermaphyte strains in their 2013 study. This study found that in vitro, terbinafine was the most potent antifungal against a number of dermaphytes.