Effectiveness and safety of oral terbinafine for dermatophyte distal subungual onychomycosis

Expert Opin Pharmacother. 2024 Jan-Apr;25(1):15-23. doi: 10.1080/14656566.2024.2305304. Epub 2024 Feb 1.

Abstract

Introduction: Terbinafine has been a cornerstone in dermatophyte infection treatment. Despite its global efficacy, the emergence of terbinafine resistance raises concerns, requiring ongoing vigilance.

Areas covered: This paper focuses on evaluating the efficacy and safety of terbinafine in treating dermatophyte toenail infections. Continuous and pulse therapies, with a 24-week continuous regimen and a higher dosage of 500 mg/day have demonstrated superior efficacy to the FDA approved regimen of 250 mg/day x 12 weeks. Pulse therapies, though showing comparable effectiveness, present debates with regards to their efficacy as conflicting findings have been reported. Safety concerns encompass hepatotoxicity, gastrointestinal, cutaneous, neurologic, hematologic and immune adverse-effects, and possible drug interactions, suggesting the need for ongoing monitoring.

Expert opinion: Terbinafine efficacy depends on dosage, duration, and resistance patterns. Continuous therapy for 24 weeks and a dosage of 500 mg/day may enhance outcomes, but safety considerations and resistance necessitate individualized approaches. Alternatives, including topical agents and alternative antifungals, are to be considered for resistant cases. Understanding the interplay between treatment parameters, adverse effects, and resistance mechanisms is critical for optimizing therapeutic efficacy while mitigating resistance risks. Patient education and adherence are vital for early detection and management of adverse effects and resistance, contributing to tailored and effective treatments.

Keywords: Terbinafine; continuous therapy; onychomycosis; pulse therapy; terbinafine efficacy; terbinafine safety.

Publication types

  • Review

MeSH terms

  • Antifungal Agents / adverse effects
  • Arthrodermataceae*
  • Drug-Related Side Effects and Adverse Reactions*
  • Foot Dermatoses* / chemically induced
  • Foot Dermatoses* / drug therapy
  • Humans
  • Itraconazole / adverse effects
  • Nail Diseases* / chemically induced
  • Nail Diseases* / drug therapy
  • Naphthalenes / adverse effects
  • Onychomycosis* / drug therapy
  • Terbinafine / adverse effects
  • Treatment Outcome

Substances

  • Terbinafine
  • Itraconazole
  • Naphthalenes
  • Antifungal Agents