The FDA encouraged additional development in topical treatments for head lice infestation, especially in pediatric populations, due to the genetic resistance to the most common treatments.
In general, sponsors should conduct at least two randomized, double-blind, controlled trials to establish efficacy and safety, the agency said in guidance for industry. Use of a lice comb as part of the treatment regimen could affect efficacy; if it is to be used, the sponsor should include its specifications in the NDA.
Safety assessments for the scalp, adjacent skin and eyes should include evaluation for the presence of erythema, edema, pustules, excoriation, and a query for pruritus, both at baseline and during post-treatment visits. The FDA also identified several important safety issues with previously approved drugs, including neurotoxicity, neonatal toxicity and the inhibition of acetylcholinesterase, as well as any arrhythmogenic potential, and the effects of accidental ingestion of the topical drug.