The treatment for head lice is to use a pediculicide with an ovicidal effect, as stated by the Centers for Disease Control and Prevention, or CDC. These are medicines that not only kill the adult lice, but the eggs they lay as well.
When one member of the family gets head lice, the rest of the family should be checked as well. Any members of the family who share the same bed as the infected person are advised to undergo treatment at the same time.
Any lice treatment that does not contain an ovicide will need to be repeated to insure all the lice are killed. This retreatment should occur when all the eggs have hatched but before new eggs are produced, as stated by the Centers for Disease Control and Prevention.