Efficacy of Amorolfine in Onychomycosis Treatment: A Mixed-Effects Models and Multivariate Logistic Regression Analysis.

Background: Onychomycosis (OM) is a common nail infection treated with amorolfine hydrochloride nail lacquer in China. Monitoring drug concentrations and using dermoscopy to evaluate treatment efficacy may provide new insights.

Objective: The study aims to analyse amorolfine concentrations in nails with mild to moderate OM, assess treatment outcomes using dermoscopy and explore factors influencing drug concentrations and efficacy.

Methods: Patients with mild to moderate OM confirmed by fungal microscopy were enrolled. Amorolfine nail lacquer was applied twice weekly for 36 weeks. Monthly nail samples measured amorolfine concentrations using liquid chromatography. Dermoscopy was performed before and after treatment to evaluate responses. Mixed-effects models and logistic regression analysed factors affecting drug concentrations and outcomes.

Results: Ninety-seven nails were included. Amorolfine concentrations increased over time, with higher levels in females, fingernails, 2nd-5th digits and superficial white OM (p < 0.05). Age was a risk factor, while drug concentration and OM type were protective for clinical efficacy (p < 0.05). Peak concentration correlated with clinical (r = 0.487, p = 0.000) and mycological (r = 0.433, p = 0.000) responses. Dermoscopic features improved significantly in successful cases (p < 0.05).

Limitations: In the assessment of fungal efficacy, only fungal microscopy was used, and fungal cultures were not performed. The study was limited by a small sample size and the lack of a longer follow-up to assess relapse.

Conclusion: Amorolfine concentrations vary with patient and nail characteristics, influencing efficacy. Dermoscopy is valuable for monitoring OM treatment.