Safety of current therapies for onychomycosis.

Systemic antifungals offer greater efficacy for onychomycosis treatment but are limited by risks of systemic toxicity and drug-drug interactions. The risk of terbinafine-induced hepatotoxicity is negligible in healthy patients. Systemic therapies, especially azole antifungals, are associated with numerous drug-drug interactions, some of which are life-threatening and fatal. Thus, a detailed medication history is critical before prescribing these medications. Topical antifungals are well tolerated and generally safe, with only potential local side effects. Systemic and topical onychomycosis treatments should not be prescribed during pregnancy and breastfeeding. Laser therapy is likely less effective than systemic and topical therapies, but may be safely used during pregnancy and breastfeeding.