The U.S. Food and Drug Administration today approved Natroba (spinosad) Topical Suspension 0.9% for the treatment of head lice infestation in patients ages 4 years and older.

Head lice are parasitic insects found on people’s head, eyebrows, and eyelashes. They feed on human blood several times a day but are not known to cause disease. Head lice are spread mainly by direct head-to-head contact with a person who already has head lice. Lice move by crawling and can easily travel from child to child because children play closely together and often in large groups.

“Natroba provides another option for the topical treatment of head lice infestations, which are especially prevalent in the pediatric population,” said Julie Beitz, M.D., director of the Office of Drug Evaluation III in the FDA’s Center for Drug Evaluation and Research. “Head lice is a common problem among school children in the United States.”

Natroba is a topical drug product and should be applied only to the child’s scalp or hair. The product should be used exactly as prescribed by a health care professional.

The safety and effectiveness of Natroba Topical Suspension 0.9 %, has been established in two multicenter, randomized, active-controlled studies. A total of 552 subjects received a 10-minute treatment with Natroba. If live lice were seen a week later, a second treatment was applied. The proportion of subjects who were lice-free fourteen days after the final treatment of Natroba was approximately 86 percent compared to 44 percent of 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. Although Natroba is not approved for use in children younger than 4 years, it is especially important not to use in infants because the product contains benzyl alcohol. Systemic exposure to benzyl alcohol has been associated with serious adverse reactions and death in neonates and low-birth weight infants.

Natroba is manufactured for ParaPRO LLC of Carmel, Ind.