Bristol-Myers Squibb's cephalosporin antibiotic cefipime has an 84% clinical success rate, compared to a 75% clinical success rate for ceftazidime, in interim results from a Phase III cost- effective trial presented Dec. 5 by principal investigator Joseph Paladino, State University of New York at Buffalo. Bristol-Myers filed an NDA for cefipime in June 1992. Ceftazidime is marketed by Glaxo (Fortaz, Ceptaz), Lilly (Tazidime) and SmithKline Beecham (Pentacef, Tazicef). Paladino spoke at a symposium supported by an unrestricted BMS grant, entitled "Challenges in Antibiotic Formulary Management," prior to the American Society of Hospital Pharmacists' midyear clinical meeting in Atlanta. Moderator John Boss, Medical University of South Carolina, disclosed that the Bristol-Myers "did offer input and advice in terms of speakers and content." Paladino's cost-effectiveness study of cefipime versus ceftazidime has enrolled 96 septic patients with bacterial infections; 82 of the patients were evaluable at the time of his presentation. In terms of sites of infection among the patients, there was bacteremia "usually associated with an underlying infection which would include pneumonia and urinary tract" infection, Paladino said. There were a total of 104 infections among the 96 patients. Paladino's estimates put mean drug and infection-related costs at $238 for cefipime and $284 for ceftazidime in preliminary results. Including antibiotic-related hospital stays, mean costs were calculated to be $7,798 with cefipime compared to $9,035 with ceftazidime. Mean length of antibiotic-related stay was two days less among the cefipime-treated patients, Paladino reported. The SUNY-Buffalo researcher based his cost estimates on a price of $10.50 per gram for cefipime injectable and $9 per gram for ceftazidime. The cefipime price he "pulled out of the air," guessing that BMS will be "competitive with their price," Paladino explained. "Probably both of these [cost estimates] are low," he added. Drug administration and preparation costs were estimated at $4 per dose. "There was a little bit of a heavier use of [every eight hours] regimens with ceftazidime and [every 12 hours] with cefipime," Paladino observed. Hospitalization costs were calculated at $752 per day, derived from American Hospital Association figures on the average cost of stay in the U.S. in 1991. Mean costs included costs of therapy with a second antibiotic in the case of treatment failure, factored in at the actual cost of that therapy. When Paladino did a sensitivity analysis by varying his cost figure for both drugs between $9 and $14, "drug price did not change the decision...consistently cefipime was the pharmacoeconomic winner," he asserted. When the success rates of the two drugs were varied between 60% and 98%, Paladino found that, based on the preliminary data gathered at his institution, "ceftazidime had to average 10% more efficacy than cefipime in order to be cost-effective." Thomas Hardin, University of Texas Health Science Center, San Antonio, discussed in vitro data on cefipime at the Dec. 5 symposium. Hardin observed that the cefipime molecule, while having an overall neutral charge, is zwitterionic, containing a positive and negative charge in different sections of its structure. Ceftazidime and cefotaxime (Hoechst-Roussel's Claforan) both are negatively charged overall. Cefipime's structure "adds to increased penetration into the organism, a greater affinity for binding to the desired protein binding site, and a reduced affinity for the enzymes that break it down," Hardin asserted. In terms of in vitro MIC[50] (minimum inhibitory concentration) values, cefipime in some ways combines "the anti-pseudomonal activity of ceftazidime and the increased potency against gram-positive bacteria of cefotaxime in a single cephalosporin," Hardin concluded. Bristol-Myers Squibb is seeking indications for cefipime including community-acquired and nosocomial pneumonias, acute bronchitis, urinary tract infections, skin and skin structure infections, bacteremia, sepsis and febrile neutropenia, Hardin told the pharmacists at the meeting. In highlighting some new antibiotic classes in earlier clinical trials, Hardin suggested that streptogramins could offer some "interesting hope" in the treatment of methicillin-resistant staphylococcal infections and vancomycin-resistant enterococci. Streptogramins "have a somewhat unique mechanism of action: they bind irreversibly to the bacterial ribosome and inhibit protein synthesis," the UT Health Science Center researcher explained. "To date, there has been no cross resistance shown between the streptogramins and beta lactams, the macrolide antibiotics or the glycopeptides like mitomycin," Hardin told the group. Rhone-Poulenc Rorer is currently in Phase II trials with its two-component injectable streptogramin Synercid, also known as RP 59500. Hardin concluded his presentation by noting that if health care providers "rapidly embrace the use of...newer antibiotics for questionable indications, we're going to be contributing further to the problems that got us to this point to begin with...that is, further resistance development."