Spinosad topical suspension (0.9%): a new topical treatment for scabies

Introduction Scabies is a highly contagious skin disease caused by the parasitic mite Sarcoptes scabiei. There is no vaccine and for the past 30 years, the first line treatments have been topical permethrin and oral ivermectin. These drugs target mainly the parasite nervous system, killing only the motile stages. As they lack ovicidal activities, repeat treatments are required to achieve complete cure. Incompliance to repeat treatments causing prolonged drug usage has contributed to emerging drug resistances. In addition, they are not appropriate for all patient categories, specifically for infants and young children or pregnant and breast feeding women. Consequently, new single-dose scabicides are urgently needed. Areas covered In 2021, spinosad, a drug previously used to treat head lice, was approved by the US FDA as a topical scabies treatment. Here the pharmacology, clinical efficacy, and tolerability of this drug are discussed. Expert opinion As the first single-dose scabicide, the formulated 0.9% topical Spinosad solution shows significant efficacy, little systemic absorption, and no serious adverse reactions, making it a promising treatment for classical scabies in patients older than four years.