Utility of Baseline Transaminase Monitoring During Systemic Terbinafine Therapy for Pediatric Onychomycosis—Reply

In Reply We appreciate the comments of Li and Mostaghimi regarding our study. While we generally agree that baseline monitoring of laboratory values in children prior to systemic therapy for onychomycosis may not be cost-effective or informative in otherwise healthy children, we would like to emphasize that, in our opinion, clinicians should be adherent to medication-use directives and current guidelines for patient safety, which at this time are unambiguous with regard to the recommendation for pretreatment laboratory screening for terbinafine. The package insert, which was last revised in January 2017, states "before prescribing Lamisil Tablets, perform liver function tests because hepatotoxicity may occur in patients with and without preexisting liver disease." Furthermore, the US Food and Drug Administration medication guide for terbinafine, which was last issued in August 2016, states "your doctor should do a blood test to check you for liver problems before you start treatment with LAMISIL Tablets." With these guidelines in place, we currently do not feel comfortable, based on this one study, to advise clinicians to dismiss these recommendations. Importantly, this study does give us the opportunity to open up lines of communication with the US regulatory bodies to consider altering the terbinafine medication guidance specifically for pediatric patients and consider additional studies that would help solidify these data. We want to maintain the highest standard of care and safety for the treatment of pediatric patients while continuing to practice cost-effective and evidence-based medicine.