Patrick J. Skerrett

FDA approves new treatment for head lice

Good news for parents, teachers, pediatricians, and others engaged in the ongoing battle against lice: the FDA just approved a new treatment for head lice in children age four and older. Called Natroba, it’s a liquid that is rubbed into the hair and allowed to sit for 10 minutes before being rinsed off. Natroba is a useful addition to the anti-lice arsenal, since some head lice have become resistant to permethrin and pyrethrins, the active ingredients in over-the-counter anti-lice products such as Nix and Rid.

CDC photo of the stages of the life of a head louse, with a penny for size comparison.

Head lice are tiny insects that go by the big name Pediculus humanus capitis. They thrive in the warm tangle of human hair, feeding off blood in the scalp and breeding with abandon. A female lays eggs called nits that she attaches to strands of hair. Nits hatch after about eight days, become adults in another week or so, feed for awhile, then begin to make more lice.

What to do

First off, here’s what not to do: don’t shave your or your child’s head, or coat it with petroleum jelly or mayonnaise or anything else designed to “suffocate” the parasite. You’ll probably end up with greasy, smelly, lice-infested hair.

Current guidelines from the American Academy of Pediatrics call for the use of an over-the-counter product containing permethrin or pyrethrins as a first salvo against head lice. Shampoos and rinses made with these substances are generally effective. Most treatments for head lice need to be used twice, seven to 10 days apart, along with combing wet hair with a fine-toothed nit comb. Some lice are resistant to pyrethrin and permethrin. Stronger prescription drugs, such as malathion and lindane, also work but aren’t as safe for humans. That’s where Natroba comes in.

The active ingredient in Natroba is spinosad, a chemical derived from a naturally occurring bacterium collected in the soil around an abandoned rum distillery in the Caribbean by a vacationing scientist. It has proven to be an effective pesticide that has little effect on humans. The most common side effect in the trials was redness or irritation of the skin or eyes.

Natroba, which will be sold as a prescription medication, is applied to the head for 10 minutes, then washed out. It does not require combing as part of the treatment, which will make many parents–and their kids–exceedingly happy. In two clinical trials conducted among 552 children with head lice, 86% were lice-free after one or two treatments with Natroba, compared to 44% with a 1% permethrin treatment. The product will be available later this year.

If you are worried about chemicals, don’t ignore the value of a nit comb. A study published in the British Medical Journal in 2005 showed that combing out the hair with a fine-toothed comb (the “Bug Buster”) immediately after using conditioner worked better than a single treatment of an over-the-counter insecticide.

Although Natroba looks like an interesting and effective new product, I wouldn’t be the first on my block to try it if my children or I had lice. It’s the same caution I give readers of the Harvard Heart Letter when it comes to newly approved drugs and devices. The clinical trials that led to the approval of Natroba included fewer than 600 children who used it once or twice. We will undoubtedly learn more about the drug—its effectiveness, side effects, safety, and interactions with other drugs—after it has been used by hundreds of thousands of people. With other effective treatments out there, a wait-and-see approach makes sense.

To learn more about head lice and what to do about them, the Centers for Disease Control and Prevention has excellent information online.

Comments:

  1. Mary

    At my child’s school in the San Diego Unified School District the school will not notify the parents if there are lice in the classroom, and do not perform checks of the class when an infestation is reported, the burden is left completely up to the parents to simply deal with it when our children get lice, it is a pretty hopeless and frustrating situation! The SDUSD says in response to my plea that they bring back the lice checks or stop using headphones communally amongst the students, “I would actually be more concerned about possible exposure to other kinds of communicable diseases than head lice, such as colds and flu, due to students not washing their hands when using them or having those kinds of germs on their skin.” I think only a person who had never had lice could say such an ignorant thing! I would rather have 10 colds than 1 case of lice.

  2. Sheridan

    What is the treatment if a hospitalized patient with dreadlocks has lice?

  3. Anonymous

    Terry Rowe you kids aren’t becoming reinfected a week later you didn’t get rid of it in the first place! Combing isn’t effective for most people. They are insects. You need to kill them! I’m sick of parents sending their kids to school and out in public with lice, including nits. That is why lice is such a huge problem. While it’s good they’ve come out with a new insecticide I refuse to use any prescription required product as I find it offensive and oppressive. Must be nice creating cash cows and a delusional sense of superiority. I resent the invasion of privacy as well. It’s the principle.

  4. Terry Rowe

    Thanks for the info about head lice
    My kids get it constantly from school..I clean it up and send them back to school, only to have them get it again the next week.
    I will certainly try Natroba or Spinosad next time

  5. Rattan

    Whoa… that was one great lice story and effective treatment.

  6. Jolene Schweigert

    thanks for your thoughts on this, I felt a bit struck by this article. Thanks again!

  7. arsenal

    Many people overreact with lice and want to disinfect and fumigate their whole home. Lice can’t live away from hosts for more than a day or two because they can’t feed. The nits usually die within a week when they are not near the warm temperatures found on the scalp. You should wash clothing that the infested person has worn for a couple of days before treatment, and their towels and bedding should be washed, too, using hot water (130 F). A simple vacuuming the floor and furniture will pick up nits and lice that may have fallen off the infested person. Of course, brushes and combs should be soaked in hot water (130 F) for several minutes.
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  8. Ariana

    We have been dealing with seasonal outbreaks for several years now — frustrating, expensive — hours of combing, laundry & vacuuming only to have a reinfection brought home two weeks later! Just tried naproxen on myself yesterday & didn’t comb through. (also nervous about using it on my kids yet) Will see in a week whether it works any better…

    • Carrie

      Let me know how that works out. My grandaughter seems to attract the rotten little critters. I am in the process of combing and combing! Her hair and my two youngest daughters! Ugh and still going to work! Thank goodness for a helpful husband around the house!

  9. Anonymous

    Many people overreact with lice and want to disinfect and fumigate their whole home. Lice can’t live away from hosts for more than a day or two because they can’t feed. The nits usually die within a week when they are not near the warm temperatures found on the scalp. You should wash clothing that the infested person has worn for a couple of days before treatment, and their towels and bedding should be washed, too, using hot water (130 F). A simple vacuuming the floor and furniture will pick up nits and lice that may have fallen off the infested person. Of course, brushes and combs should be soaked in hot water (130 F) for several minutes.
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  10. Home remedies for head lice

    Hi thanks for letting us know about this new treatment for lice, however as you say I would be unwilling to test this out on my kids. I’ve gathered two remedies (none of the ones you mentioned – well one uses oil but has other things too) and lots of people have found them effective, although they do involve using the nit comb (but I think you are supposed to do that with all treatments?), one is with olive oil, tea tree and lavender and the other with rubbing alcohol or mouth wash.
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  11. Nicki Min

    Thanks for the heads up P.J.!
    We are having a constant trouble with a head lice – my daughter keep getting them from school every month(sometimes twice a month). Cost me quite a bit of money and hassle :) because shes got a long very thick curly hair and doesn’t want to cut it short :)
    We tried everything, repellents you name it…still she brings them :(
    But i try Natroba if its available here in the UK

  12. tracy

    What I really like about this product is that it only takes 10 minutes- then you are ready to rinse. Parents can say goodbye to hours spent combing their child’s hair with a fine toothed comb. But the bast thing, of course, is that it is FDA approved. This assures the quality and safety of the product.

  13. Hair Replacement Service

    It’s always refreshing to know of products that really helps mothers a lot how to solve their child’s trouble like head lice! I too have been scratching my head when I was still I kid. It terribly hurt a lot!
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  14. Daniel Har

    What about a solution with vinegar? Coming from Romania, that’s what they used in villages and it was very effective.

    • Patrick J. Skerrett
      P.J. Skerrett

      Daniel — Vinegar may have seemed effective compared to no treatment at all. But a comparison of six home remedies (vinegar, isopropyl alcohol, olive oil, mayonnaise, melted butter, and petroleum jelly) to treat head louse infestations found that none of the treatments prevented lice from laying eggs, nor did they do much to kill eggs, even when the treratment was applied to the head for long periods. The researchers, from the Center for Vector-Borne Diseases at the University of California, Davis, concluded, “None of the home remedy products we surveyed was an effective means of louse control. This suggests that when treatment failure occurs, an increased amount of time and effort should be focused on alternative chemical pediculicides and/or manual louse removal (i.e., combing) rather than using any of these products.”

  15. Helen Hoart

    I second the recommendation from the British Medical Journal. When my kids had head lice, I used the over the counter treatments and they didn’t help. But lots of conditioner and lots of combing did the trick.

  16. Tom Guard

    Spinosad is relatively fast acting. The insect dies within 1 to 2 days after ingesting the active ingredient. So far, there appears to be 100% mortality. It works by acting on the central nervous system of the organism.