A study published in 2003 reported that ivermectin is safe for people in high-risk categories, including those with compromised immune systems.
In addition to topical medications, the doctor may prescribe oral ivermectin, a drug that was originally developed for veterinary practice as a broad-spectrum antiparasite agent.
Ivermectin (Stromectol), an oral treatment for intestinal parasites, is effective against head lice but as of 2004 had not been approved for that use by the FDA.
Ivermectin is a similar medication which treats mange, ear mites and heartworm prevention.
Ivermectin is often given under the brand name Heartguard, and Milbemycin oxime is often prescribed under the brand names Interceptor and Sentinel.
Studies done in humans, however, have found that ivermectin is as safe and effective as topical medications for treating scabies.
The drugs used in oral prescription medications include either ivermectin or milbemycin oxime.