ABBOTT's TRANXENE "ANXIOSELECTIVE" PROMOTION ENDING: FDA SAYS NO CLINICALLY SIGNIFICANT DIFFERENCE EXISTS BETWEEN TRANXENE & OTHER ANXIOLYTICS

Abbott is discontinuing its promotion of Tranxene (clorazepate dipotassium) as "anxioselective" after a year-long debate with FDA about the appropriateness of the term. In a June 25 letter to the agency, Abbott said "all promotional use of the term 'anxioselective' has been halted." The firm added: "We expect, however, should this term become acceptable in the future, that we will be permitted to utilize it consistent with your determinations." FDA first objected to Abbott's use of the term "anxioselective" in a July 16, 1984 letter. In the agency's most recent correspondence, dated June 17, 1985, FDA Rx Drug Advertising & Labeling Div. Director Lloyd Millstein, PhD, reiterated that the term has no "real, inherent, meaning" and has been inappropriately used by Abbott "to- represent or suggest quantitative differences of clinical importance between anxiolytic agents." "Since you proclaim a lack of desire to compare Tranxene with other agents of its class," Millstein told Abbott, "we will not herein address any such comparability other than to note that none of the materials reviewed adequately demonstrate any clinically significant difference between Tranxene and any other drug product of its class currently marketed in the U.S." Millstein said the agency's Neuropharmacologic Division reviewed the data on Tranxene and, citing The Pharmacologic Basis of Therapeutics, concluded that since editors Goodman and Gilman "suggest that a label of 'selective' can be used to roughly categorize a drug 'by its most prominent effect or by the action thought to be the basis of that effect,' the term anxioselective implies nothing more than that a drug so labeled would be most prominently characterized by a decrease in anxiety symptoms. The term would then be appropriately applied to all benzodiazepines, as well as many other drugs whose actions feature sedative/hypnotic effects." Thus, FDA stated, "the term 'anxioselective' would be roughly equivalent to the term 'anxiolytic,' and would be an unnecessary addition to the vocabulary of psychopharmacology." In an April 23 letter to FDA, Abbott Regulatory Affairs Director John Dybas argued that "the Goodman and Gilman definition and our use of the term anxioselective do not suggest either any comparisons between the degree of selectivity of Tranxene and other drugs used to treat anxiety or that Tranxene is the only anxioselective anxiolytic." The company reiterated that it would define the term in labeling and promotion as referring to a drug "whose most prominent action is anxiety reduction with less prominent other behavioral consequences." Abbott further maintained that "anxioselective" was analogous to claims of selectivity by certain cardioactive drugs. FDA had told the firm previously in an Aug. 31, 1984 meeting that such a comparison could not be made since "various alpha and beta agents have demonstrated pharmacological selectivity in certain instances which have clinical significance" while there are no studies "demonstrating similar pharmacological differences between Tranxene and other anxiolytic products." FDA recorded its objections to the anxiolytic/cardioactive analogy in a memo of the Aug. 31 meeting. Abbott also agreed at the request of FDA to discontinue its claims that Tranxene does not cause "problem sedation" andjor that the drug restores or maintains alertness. In the agency's June 17 letter, Millstein asserted that Abbott "not only failed to demonstrate the validity and applicability of [anxioselective] to Tranxene brand products, but has actually provided information demonstrating that Tranxene is clearly associated with various side effects in contradiction to the promotional claims purveyed by [the] firm at least over the past five years." Commenting on a study by Buchsbaum, which Abbott cited in support of its claims for Tranxene, the agency said in Feb. 20, 1985 correspondence that "while there is no disagreement with Dr. Buschbaum's findings of increased beta activity following administration of Tranxene we sharply disagree with the stated conclusions that this is indicative of 'alertness.' As noted in [Current Practice of Clinical Electroencephalography, edited by Klass and Daly] . . . sedative agents cause an increase in Beta activity." In addition, FDA said "disagreement is also found with Buchsbaum's association of increased Delta activity with drowsiness. According to the same text, Delta activity slows with higher levels of sedative drugs." FDA stated in the Feb. 20 letter: "If it is your contention that Tranxene traverses the range from anxiety to alertness, stopping short of relaxed wakefulness, drowsiness and sedation . . . which we suspect to be the sole basis of your claims of 'anxioselectivity' and 'restores alertness,' be advised that you have not provided data sufficient to adequately support such a theory. In fact, the data supplied appears to support the labeling which includes sedation as a potential adverse reaction, and which would be expected from this class of drugs."