Question: what is the best medicine to kill lice?
Answer: Benzyl alcohol (Ulesfia). This lotion kills active lice, not eggs. ... 
Ivermectin (Sklice). This lotion kills most head lice, even just-hatched lice, with just one use. ... 
Malathion (Ovide). This very strong lotion paralyzes and kills lice and some lice eggs. ... 
Spinosad (Natroba).