The Food and Drug Administration (FDA) today issued a Public Health Advisory concerning the use of topical formulations of Lindane Lotion and Lindane Shampoo for the treatment of scabies and lice. The advisory announces significant updates to the labeling of these products. These labeling changes include additional warnings and the addition of a Medication Guide to be distributed directly to patients.
Labeling for Lindane products has been changed to include a boxed warning which highlights the most important safety issues associated with use of these products. The boxed warning contains information to better inform both healthcare professionals and patients regarding the potential risks associated with the use and misuse of Lindane.
The warning emphasizes that Lindane products have been, and continue to be, indicated as a second-line therapy for the treatment of scabies and lice. While FDA believes that the benefits of Lindane outweigh the risks when used as directed, given the potential for neurotoxicity, patients should only be treated with these medications if other treatments are not tolerable or other approved therapies have failed.
The new boxed warning also states that Lindane Lotion and Lindane Shampoo are to be used with caution in patients who weigh less that approximately 110 pounds (50 kilograms). These products are not recommended for use in infants, and are contraindicated in premature infants. These warnings are based on reports to the FDA’s voluntary reporting system which described approximately one half of reported adverse events occurred in pediatric patients.
It is estimated that in the United States up to 1 million prescriptions are written each year to treat new cases of head lice and scabies, which occur mostly in school-age children. Since Lindane is absorbed through the skin, and because younger children have more skin surface area per pound of body weight than adults, the amount that is absorbed may result in higher blood levels of Lindane in children than that seen in adults. Animal studies have also shown that younger animals are more susceptible to the neurological side effects seen with Lindane use.
Because most of the serious adverse events reported with Lindane products are due to misuse and overuse, especially with the Lotion, product package sizes will be limited to 1 and 2 ounces. It is very important that patients understand the importance of using this medication in a manner consistent with the product labeling.
The instructions for use and information about adverse events will also be provided to patients in the form of a Medication Guide. By law, the Medication Guide must be dispensed by pharmacists directly to the patient with each new prescription of Lindane Lotion or Lindane Shampoo.
Other changes in the labeling address FDA concerns of potential increased risk of adverse reactions associated with the use of Lindane products in immuno-compromised patients, such as those with HIV infection, or patients on medications, such as antidepressants, that may increase the chances of having a seizure.
Given the possible risks associated with the use of Lindane, healthcare providers should consider this new safety information when deciding whether to prescribe Lindane Lotion or Lindane Shampoo for patients who may be at risk for serious adverse drug events.