BURROUGHS WELLCOME TRACRIUM "MISLEADING COMPARATIVE CLAIMS" CITED

BURROUGHS WELLCOME TRACRIUM "MISLEADING COMPARATIVE CLAIMS" CITED by FDA in a July 31 warning letter. The agency says in the letter that Burroughs Wellcome has distributed brochures and other promotional materials for the nondepolarizing neuromuscular blocker that contain "comparisons based on data collected in different clinical studies instead of data collected from the same study comparing different treatments." FDA also cited the company for making clinical superiority claims for Tracrium (atracurium besylate) "on the basis of pharmacokinetic differences that have not been shown to have clinical significance. In addition, FDA said the company based "comparative claims on published reports that do not support such claims." The agency said it is evaluating other aspects of Burroughs Wellcome's promotional campaign for Tracrium and that "additional violations may be identified." FDA told the company that "the overall manner in which [it] has engaged in the promotion of this product must be changed." FDA also asked Burroughs Wellcome to submit its plans to discontinue the violative materials, including instructions to its sales force. FDA noted in the letter that there is a "long history of competition among various firms marketing products in this therapeutic category, and the resulting incidence of promotional claims violative of the [FD&C] Act." However, FDA emphasized that a warning letter to one of the competitors in the field "is not in any way to be construed as an attempt by the agency to interject itself as arbiter in marketing disagreements between firms." Burroughs Wellcome's major competitor in this area has been Organon, with its product Norcuron (vecuronium). FDA said that it has also had discussions with Organon regarding the company's inappropriate promotions, which have been discontinued. One brochure distributed by Burroughs Wellcome used pharmacokinetic data to imply clinical superiority and safety over two other neuromuscular blockers, pancuronium and vecuronium, FDA said. A chart in the brochure shows plasma decay curves for the three drugs. Although the brochure states that "peak plasma concentration of pancuronium is much lower because a smaller dose had been given," FDA maintained that the depiction is misleading "because the chart graphically implies that the two products were given in equipotent doses." FDA also criticized the brochure for taking the data on the three products from different sources instead of head-to-head comparisons. Because the data were not from direct comparisons, FDA said that the brochure's statement -- "rapid elimination means easy reversal and fast, complete recovery" -- is misleading when used with the chart. FDA noted that another chart in the brochure, on a page claiming that Tracrium has the most consistent pharmaco- dynamics of any nondepolarizing neuromuscular blocker, derives its information from sixteen different sources. A Burroughs Wellcome reprint carrier showing that there is no difference between Tracrium and vecuronium in serum histamine is also misleading, FDA contended, because the finding is based on an article published in Anesthesiology Review that discussed ways of dealing with histamine release, not comparison of release times. "The implication that the article supports a claim of no difference [in histamine release between Tracrium and vecuronium] is misleading," FDA declared. The warning letter also mentions reference registration forms bearing Burroughs Wellcome's logo that were used at the American Society of Anesthesiologists' 1990 annual conference as well as at a University of Michigan symposium. Questions posed in the forms "are promotional in nature and are therefore considered labeling," FDA said. The agency noted that there were not adequate directions for use of the product alluded to in the questions.