Oral ivermectin, malathion and other treatments: literature roundup

A round-up of literature over the last couple of years covering diverse methods of treating pediculosis.

Oral ivermectin & malathion

Two 2010 papers give further information on in vivo tests on the efficacy of oral ivermectin and malathion for treating head lice:

The work of Nofal, published in 2010 in the Journal of the German Society of Dermatology tested 80 children; giving half of them a dose of oral ivermectin (200 mcg/kg) and half a treatment with a 0.5% malathion solution. Success rates after 8 days were 77% (ivermectin) and 87% (malathion) respectively.

After administering a second dose to unresponsive patients, follow-ups at day-15 after initial treatment gave a success rate of 92% and 95% for ivermectin and malathion respectively. The paper considers oral invermectin to be a 'promising' treatment.

The work of Chosidow et al. was published in the New England Journal of Medicine and involved a multi-centre RCT using a much greater patient group than the Nofal study. 812 patients were involved in total, all receiving a dose of either oral ivermectin (400 mcg/kg) or malathion (0.5% solution) on days 1 and 8 of the study. Follow-up two weeks after treatment found that, for intention-to-treat patients, of the ivermectin group, 95% were lice-free, compared to 85% for the malathion group (significant at <0.001 level). The authors recommend oral ivermectin as an alternative to malathion due to its 'superior efficacy'.

Neem seed extract

A recent paper from Adbel-Ghaffar et al. published in Parasitology Research in 2012 investigated neem seed extract as a pediculicide both in vivo and in vitro. This small study, involving 12 children, found that a 10-minute treatment with the product was sufficient to kill all lice infestation, with no lice found on day-8 post treatment. The authors suggest, based on this and on in vitro experiments, that the neem seed extract is effective against head-lice and that it has an ovicidal activity as well.

Other studies

A study published by Grieve & Barnes in Parasitology Research in 2011 compared four commerical products for their ability to prevent the transmission of head lice in vitro. The tests showed that none of the products could completely prevent lice motility into treated areas, but found that 'MOOV spray' was the most consistent and efficient at discouraging lice motility.

Finally, a wider-ranging study by Asenov et al. published in the International Journal of Dermatology in 2010 compared several commercial pediculicides for efficacy using an ex vivo experiment. They concluded that two of the 1% permethrin products showed the greatest lice mortality (>90% after 4h). Several other 1% permethrin products, as well as two 0.02% deltamethrin products showed efficacy of <60%. A pure coconut oil treatment had an 80% efficacy rate, while several OTC products tested showed low efficacy.