The U.S. Food and Drug Administration (FDA) has approved spinosad (Natroba) topical suspension 0.9% for the treatment of head lice infestation in patients aged 4 years and older.

According to the FDA report, the safety and effectiveness of spinosad suspension 0.9%, has been established in two multicentre, randomised, active-controlled studies. A total of 552 subjects received a 10-minute treatment with spinosad. If live lice were seen a week later, a second treatment was applied. The proportion of subjects who were lice-free 14 days after the final treatment of spinosad was approximately 86% compared to 44% in the control group.

Common adverse events reported include redness or irritation of the eyes and skin. Safety in pediatric patients below the age of 4 years has not been established and use in patients under this age is contra-indicated especially because the product contains benzyl alcohol.