Efficacy of topical resin lacquer, amorolfine and oral terbinafine for treating toenail onychomycosis: a prospective, randomized, controlled, investigator-blinded, parallel-group clinical trial

• Published in: British journal of dermatology (1951) Vol. 173; no. 4; pp. 940 - 948
• Main Authors: Auvinen, T., Tiihonen, R., Soini, M., Wangel, M., Sipponen, A., Jokinen, J.J.
• Format: Journal Article
• Language: English
• Published: England Blackwell Publishing Ltd 01.10.2015; Oxford University Press
• Subjects: Administration, Oral; Administration, Topical; Adult; Amorolfine; Antifungal agents; Antifungal Agents - administration & dosage; Antifungal Agents - adverse effects; Clinical trials; Drug Administration Schedule; Drug Therapy, Combination; Female; Foot Dermatoses - drug therapy; Humans; Lacquer; Male; Morpholines - administration & dosage; Morpholines - adverse effects; Naphthalenes - administration & dosage; Naphthalenes - adverse effects; Onychomycosis; Onychomycosis - drug therapy; Oral administration; Patients; Picea abies; Prospective Studies; Resins, Plant - administration & dosage; Resins, Plant - adverse effects; Single-Blind Method; Terbinafine; Toenail; Treatment Outcome; Young Adult
• ISSN: 0007-0963; 1365-2133
• DOI: 10.1111/bjd.13934

Summary Background Norway spruce (Picea abies) produces resin to protect against decomposition by microbial pathogens. In vitro tests have shown that spruce resin has antifungal properties against dermatophytes known to cause nearly 90% of onychomycosis in humans. Objectives To confirm previous in vivo observations that a topical resin lacquer provides mycological and clinical efficacy, and to compare this lacquer with topical amorolfine hydrochloride lacquer and systemic terbinafine for treating dermatophyte toenail onychomycosis. Methods In this prospective, randomized, controlled, investigator‐blinded study, 73 patients with onychomycosis were randomized to receive topical 30% resin lacquer once daily for 9 months, topical 5% amorolfine lacquer once weekly for 9 months, or 250 mg oral terbinafine once daily for 3 months. The primary outcome measure was complete mycological cure at 10 months. Secondary outcomes were clinical efficacy, cost‐effectiveness and patient compliance. Results At 10 months, complete mycological cure rates with the resin, amorolfine and terbinafine treatments were 13% [95% confidence interval (CI) 0–28], 8% (95% CI 0–19) and 56% (95% CI 35–77), respectively (P ≤ 0·002). At 10 months, clinical responses were complete in four patients (16%) treated with terbinafine, and partial in seven (30%), seven (28%) and nine (36%) patients treated with resin, amorolfine and terbinafine, respectively (P < 0·05). Resin, amorolfine and terbinafine treatments cost €41·6, €56·3 and €52·1, respectively, per patient (P < 0·001). Conclusions Topical 30% resin lacquer and topical 5% amorolfine lacquer provided similar efficacy for treating dermatophyte toenail onychomycosis. However, orally administered terbinafine was significantly more effective in terms of mycological cure and clinical outcome than either topical therapy at the 10‐month follow‐up. What's already known about this topic? Treatment of dermatophyte onychomycosis is a clinical challenge. Treatment failure is observed in 25–60% of patients with the current gold‐standard treatment, orally administered terbinafine. When applied as a monotherapy, topical antifungals have shown limited results in treating dermatophyte onychomycosis, with < 30% overall mycological cure rates; however, more than half of patients with onychomycosis are treated with topical preparations. What does this study add? This is the first clinical trial to investigate the efficacy and safety of a 30% lacquer prepared from Norway spruce (Picea abies) in the treatment of dermatophyte onychomycosis. This treatment was comparable with the most effective topical treatment currently on the market: synthetic amorolfine hydrochloride. On the basis of mycological and clinical cures at 10‐month follow‐up, orally administered terbinafine was significantly more effective against onychomycosis than either topical therapy. Linked Comment: Yong, Br J Dermatol 2015; 173: 888–889.