OTC MENSTRUAL TENTATIVE FINAL MONOGRAPH CONCURS WITH PANEL REPORT: CAFFEINE, AMMONIUM CHLORIDE AND PAMABROM ARE CATEGORY I DIURETICS

FDA's tentative final monograph for menstrual drug products classifies three ingredients, all diuretics, in Category I: ammonium chloride, caffeine and pamabrom. A number of analgesic ingredients are also Category I for relief of premenstrual/menstrual pain. However FDA moved review of those ingredients under the rulemaking for internal analgesics, antipyretics and antirheumatics. The TFMs for both product classes are published in the Nov. 16 Federal Register. Under the analgesic TFM, six ingredients were given Category I status for menstrual and other pain relief indications: aspirin, acetaminophen, carbaspirin, choline salicylate, magnesium salicylate and sodium salicylate (see story, p. 7). The only ingredient change in the menstrual TFM from the panel report is the move of pyrilamine in combination products from Category I to Category III. FDA rejected two studies submitted by Chattem to support Category I classification of pyrilamine because the statistical analysis of the studies did not take into account their crossover design ("The Pink Sheet" Aug. 22, T&G-7). The ingredient is contained in Chattem's Premysyn PMS, a combination product for premenstrual pain that also includes acetaminophen and pamabrom. In the advanced notice of proposed rulemaking (ANPR), published in 1982, FDA said it was not aware of any marketed single ingredient pyrilamine products for menstrual or premenstrual symptoms, and that such products should not be introduced during the process of the menstrual drug product rulemaking. FDA reaffirmed that position in the TFM, stating that no single ingredient pyrilamine products should be marketed for menstrual symptoms "until the agency considers the ingredient to be generally recognized as safe and effective." The TFM adds phenyltoloxamine citrate, which had not been reviewed by the panel, to the list of Category III ingredients. Because the ingredient has been marketed for menstrual/premenstrual symptoms in combinations with acetaminophen or acetaminophen with aspirin, FDA "agrees that ... that is is reasonable to include phenyltoloxamine citrate in Category III," the TFM states. "However," FDA continued, "the data are insufficient to demonstrate that phenyltoloxamine citrate in combination with acetaminophen or acetaminophen and caffeine provides any contribution to the product's effectiveness [and] additional data will be necessary to establish the effectiveness of this ingredient for use in OTC menstrual drug products." Phenyltoloxamine citrate is contained in Rich-Vicks' Percogesic, Whitehall's Momentum muscular backache formula and Ascher's Mobigesic. Momentum is labeled exclusively for muscular aches, whereas Percogesic and Mobigesic contain general analgesic claims including relief of menstrual/premenstrual pain. In addition to the antihistamines phenyltoloxamine and pyrilamine, the TFM includes a number of Category III ingredients in other classes: diuretics theobromine sodium salicylate and theophylline; cinnamedrine HCI, a smooth muscle relaxant; and pyridoxine HCI, a vitamin. Under the combination policy established in the TFM, mentrual drug products may combine Category I analgesics or analgesic combinations with single Category I diuretics and ammonium chloride, a diuretic, with other Category I diuretics. The ANPR had proposed Category I status for 650 mg ammonium chloride with 200 mg caffeine. The TFM reclassifies the combination to Category III because the ammonium chloride dose is below the established 1 gram therapeutic dose. However, FDA noted that it "has no objection to a drug product that would contain each of these ingredients at their therapeutic dose." FDA is accepting comments on the TFM through March 16.