PEDICULICIDE FINAL MONOGRAPH LISTS PYRETHRUM EXTRACT/PIPERONYL BUTOXIDE

PEDICULICIDE FINAL MONOGRAPH LISTS PYRETHRUM EXTRACT/PIPERONYL BUTOXIDE combination as the only ingredient recognized as safe and effective for the treatment of head, pubic and body lice. Published in the Dec. 14 Federal Register, the OTC pediculicide final monograph specifies that pyrethrum extract (.17-.33%) with piperonyl butoxide (2-4%) in a nonaerosol formulation is the only active OTC lice ingredient that meets monograph conditions. The pediculicide final monograph essentially corresponds to the tentative final monograph published on April 3, 1989 in which only nonaerosolized forms of the combination of pyrethrins and piperonyl butoxide were placed in Category I (safe and effective). FDA had conditioned Category I status of pyrethrins in the 1989 TFM on the development of USP standards for the ingredient due to the possibility of variations in quality and purity of the ingredient. A USP monograph was subsequently developed that "identifies the ingredient as pyrethrum extract instead of pyrethrins and provides a current standard for the chemical constituency" of the ingredient, the final monograph points out. FDA noted that USP is currently developing a compendial monograph for piperonyl butoxide as well. Aerosolized pyrethrum extracts/piperonyl butoxide has been declared nonmonograph in the final rule. The combination in aerosol products was listed in the TFM as Category I for safety and Category III (insufficient data to permit classification) for efficacy. While the effective date for the final monograph is Dec. 14, 1994, aerosol dosage forms must be off the market by June 14, 1994. FDA dealt with all other nonmonograph pediculicide ingredients in a May 10, 1993 final rule that targeted 415 Category II (not safe and effective) and Category III ingredients from seven different OTC monographs ("The Tan Sheet" May 17, p. 3). The list of pediculicide ingredients covered in that rulemaking included benzocaine, benzyl alcohol, benzyl benzoate, chlorophenothane, aqueous coconut oil soap, copper oleate, docusate sodium, formic acid, isobornyl thiocyanoacetate, picrotoxin, propylene glycol, sabadilla alkaloids, sublimed sulfur and thiocyanoacetate. OTC pediculicide products containing those ingredients were required to be reformulated or pulled off the market by Nov. 10. Virtually all nonaerosol OTC lice treatments currently contain pyrethrum extracts/piperonyl butoxide as active ingredients with the exception of Burroughs Wellcome's Rx-to-OTC switch product Nix cream rinse, which contains 1% permethrin, a synthetic pyrethroid. Approved as a prescription drug in 1986, Nix was switched to over- the-counter availability in May 1990. Burroughs Wellcome holds a patent on permethrin that expires in May 1996. FDA also is expanding the label warning for monographed pediculicide products because of adverse reactions reported to FDA from the use of pyrethrin-containing products. According to the final rule, the new warning states: "For external use only. Do not use near the eyes or permit contact with mucous membranes, such as inside the nose, mouth, or vagina, as irritation may occur. Keep out of eyes when rinsing hair. Adults and children: Close eyes tightly and do not open eyes until product is rinsed out. Also, protect children's eyes with washcloth, towel or other suitable material, or by a similar method. If product gets into the eyes, immediately flush with water." From 1979 to February 1993, FDA received 45 reports of adverse reactions associated with pyrethrin-containing drug products through the agency's Spontaneous Reporting System. "Of these 45 reports," FDA noted, "40 involved ocular toxicity (including cornea] lesions, keratitis, uveitis, and conjunctivitis and 18 of these involved children under 10 years of age whose hair was washed with the medication (a shampoo formulation) by another person." FDA said it was revising the warning because of concern that "significant numbers of persons who apply the product on themselves or on young children do not read the label warning to avoid contact of the product with the eyes or do not exercise sufficient care to keep the product out of the eyes." The final monograph also revises the "directions" section of product labeling in response to a comment on the TFM to provide for the use of "either a special lice/nit removing comb or a fine- toothed comb to help remove dead lice or nits from hair." The agency said it has no objection to companies including a package insert or booklet on the proper use of such a comb "provided the additional information is referred to on the product label or outer carton labeling."