DIPHENHYDRAMINE CITRATE WILL BE OKAYED AS OTC ANTIHISTAMINE

DIPHENHYDRAMINE CITRATE WILL BE OKAYED AS OTC ANTIHISTAMINE in the final monograph for the product class, FDA told Miles, Bristol-Myers and Richardson-Vicks in recent letters. "The division [of OTC Drug Evaluation] intends to recommend to the commissioner that diphenhydramine citrate be included as an active ingredient in the antihistamine final monograph," FDA told the companies. The three firms had all requested Category I status for the ingredient after the tentative final monograph (TFM) for antihistamines came out in January 1985. The TFM classified the hydrochloride form of diphenhydramine in Category I but did not include the citrate form. However, FDA concluded in a separate final rule for nighttime sleep aids, published Feb. 14, that the citrate salt of diphenhydramine can be considered identical to the hydrochloride salt. In that rulemaking, the agency determined that a dose of 76 mg diphenhydramine citrate is equivalent to 50 mg diphenhydramine HCl. Diphenhydramine citrate is among the ingredients in Miles' Alka-Seltzer Plus Night-Time Cold Medicine and Bristol-Myers' Excederin PM. FDA said it will recommend the following directions for use of diphenhydramine citrate in the antihistamine monograph: "Adults and children 12 years of age and older: oral dosage is 38 to 76 mg every 4 to 6 hours, not to exceed 456 milligrams in 24 hours, or as directed by a doctor. Children 6 to under 12 years of age: oral dosage is 19 to 38 mg every 4 to 6 hours, not to exceed 228 mg in 24 hours, or as directed by a doctor. Children under 6 years of age: consult a doctor." Professional labeling for children aged 2-6 will state: "oral dosage is 9.5 mg every 4 to six hours, not to exceed 57 mg in 24 hours." * FDA is still reviewing the status of diphenhydramine HClas an antitussive. The agency recently informed Warner-Lambert that review of their petition to include the ingredient in the monograph is ongoing. "The data in support of your petition are currently being reviewed by the agency in the Division of OTC Drug Evaluation and the Division of Oncologic and Pulmonary Drug Products," FDA said. "However, because of other priorities that require the reviewers' time...the agency was unable to reach a final decision...within 180 days of the date your request was filed."