Safety of current therapies for onychomycosis

Onychomycosis is the most common nail disease seen in clinical practice. Treatment options include systemic and topical therapies, as well as devices. Following clinical and mycologic diagnosis, treatment must be individualized, accounting for disease severity, infecting organism(s), comorbidities, patient characteristics and drug/device efficacy. Safety is the most important consideration in choosing the most appropriate therapeutic modality.

This review covers currently available treatments for onychomycosis, with an emphasis on safety and tolerability. Medications and devices were analyzed for side effects, drug-drug interactions, and safety during pregnancy and breastfeeding.

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.