Skip to content
My WebMD Sign In, Sign Up

Health & Parenting

Font Size

Pill Kills Hard-to-Treat Head Lice

Stromectal Pill Beats Malathion in Killing Drug-Resistant Head Lice
By
WebMD Health News
Reviewed by Laura J. Martin, MD

March 10, 2010 -- Stromectal -- a pill containing ivermectin, a drug used to prevent heartworms in dogs -- kills head lice that are resistant to first-line treatment better than malathion-based lotion.

The finding comes from a clinical trial sponsored by Merck, which makes the parasite-killing pill.

When children bring home head lice, doctors usually recommend treatment with one of several brands of pyrethroid-based products, such as Elimite, Acticin, Nix,  A-200, Licide, Pronto, Pyrinyl Plus, Rid, and Tisit (although a recent study showed that a louse-smothering product called Ulesfia works well). But pyrethroid treatment fails if the head lice have become resistant to the pesticide.

What should you try next? The Merck trial pitted Stromectal against an alcohol-based product containing the powerful pesticide malathion (Prioderm Top).

The study enrolled 812 head lice-infected people from 376 households in the UK, Ireland, France, and Israel. Each household had already tried to get rid of the pests with a pyrethroid product. All the people in each household had an alcohol-based lotion applied to their heads by investigators -- and each took a pill -- on two occasions seven days apart.

Half the people who got the lotion got the real product and half got a sham product; half those getting pills got real Stromectal and half got an inactive placebo.

On day 15, 95% of patients assigned to Stromectal and 85% of those assigned to Prioderm Top were free of lice.

More patients preferred taking the pill to using the lotion. That isn't surprising, as the lotion had to be left in the hair for 10 to 12 hours before washing out.

There was one serious adverse event in each group. A 7-year-old girl had a seizure six days after her first dose of Stromectal and was hospitalized, then sent home with a prescription for an epilepsy drug. An 11-year-old girl had a severe headache six days after first application of malathion lotion; she was hospitalized overnight but recovered fully.

"Ivermectin may be a good alternative to malathion when topical insecticide resistance is suspected," conclude study researchers Olivier Chosidow, MD, PhD, of Pierre and Marie Curie University, Paris.

The Chosidow study appears in the March 11 issue of the New England Journal of Medicine.

Today on WebMD

Girl holding up card with BMI written
Is your child at a healthy weight?
toddler climbing
What happens in your child’s second year.
 
father and son with laundry basket
Get your kids to help around the house.
boy frowning at brocolli
Tips for dealing with mealtime mayhem
 
mother and daughter talking
Tool
child brushing his teeth
Slideshow
 
Sipping hot tea
Slideshow
Young woman holding lip at dentists office
Video
 
6-Week Challenges
Want to know more?
Chill Out and Charge Up Challenge – How to help your tribe de-stress and energize.
Spark Change Challenge - Ready for a healthy change? Get some major motivation.
I have read and agreed to WebMD's Privacy Policy.
Enter cell phone number
- -
Entering your cell phone number and pressing submit indicates you agree to receive text messages from WebMD related to this challenge. WebMD is utilizing a 3rd party vendor, CellTrust, to provide the messages. You can opt out at any time.
Standard text rates apply
Which Vaccines Do Adults Need
Article
rl with friends
fitSlideshow
 
tissue box
Quiz
Child with adhd
Slideshow