The Prescriber's Letter published by the Therapeutic Research Center and distributed to physicians and pharmacists, is one of the most widely read and respected health newsletters. In the March 1997 issue, the Prescriber's Letter had this to say about head lice: You'll see some unusual treatments for head lice… especially for persistent cases.Many parents complain about treatment failures with Nix® and other products.Researchers are starting to suspect resistance.Some physicians are resorting to new therapies… but this is causing LOTS of controversy. For example, some recommend leaving Nix® on for 4 to 8 HOURS … instead of 10 minutes. Sometimes even overnight under a shower cap. Or they prescribe Elimite® cream for head lice … and leave it on overnight too. Elimite® is five times …