A controlled study has identified that oralivermectin, an antiparasitic medicine, is more effective than malathion lotion for the management of difficult-to-treat headlice.
In the study 812 patients were randomly assigned to receive either oral ivermectin or topical malathion lotion. All the patients had head lice infestation despite topical treatment in the previous two to six weeks.
The results showed that more of the patients who received ivermectin were lice-free after 15 days compared with those receiving malathion and this difference was statistically significant.
The authors of this paper suggest that use of ivermectin should be specifically restricted to patients with difficult-to-treat headlice.
Ivermectin is not licensed for use in the UK.