Comparison of short-course (5 days) and standard (10 days) treatment for uncomplicated cellulitis.

BACKGROUND: Cellulitis is a condition routinely encountered in the primary care setting. No previous study has compared a short (5 days) vs standard (10 days) course of therapy of the same antibiotic in patients with uncomplicated cellulitis. METHODS: We performed a randomized, double-blind, placebo-controlled trial to determine if 5 days of therapy has equal efficacy to 10 days of therapy for patients with cellulitis. Of 121 enrolled subjects evaluated after 5 days of therapy for cellulitis, 43 were randomized to receive 5 more days of levofloxacin therapy (10 days total antibiotic treatment), and 44 subjects to receive 5 more days of placebo therapy (5 days of total antibiotic treatment). Levofloxacin was given at a dose of 500 mg/d. Subjects were not randomized if they had worsening cellulitis, a persistent nidus of infection, a lack of any clinical improvement, or abscess formation within the first 5 days of therapy. The main outcome measure was resolution of cellulitis at 14 days, with absence of relapse by 28 days, after study enrollment. RESULTS: Eighty-seven subjects were randomized and analyzed by intention to treat. There was no significant difference in clinical outcome between the 2 courses of therapy (success in 42 [98%] of 43 subjects receiving 10 days of antibiotic, and 43 [98%] of 44 subjects receiving 5 days of antibiotic) at both 14 and 28 days of therapy. CONCLUSION: In patients with uncomplicated cellulitis, 5 days of therapy with levofloxacin appears to be as effective as 10 days of therapy.

Prolonged stability of antimicrobial activity in peritoneal dialysis solutions.

OBJECTIVE: To evaluate the stability of the antimicrobial chemical and bioactivity of gentamicin, vancomycin, and gentamicin and vancomycin in combination, and the stability of the bioactivity of ceftazidime, admixed in standard peritoneal dialysis solutions and then maintained over a 14-day period at room temperature or under refrigeration. SETTING: Peritoneal dialysis center and microbiology laboratory at a military, teaching medical center. MEASUREMENTS: Standard peritoneal dialysate bags admixed with gentamicin, vancomycin, gentamicin and vancomycin in combination, or ceftazidime were stored at either 4 degrees C or 20 degrees C for 14 days. Sequential aliquots were withdrawn and assayed for antibiotic activity by bioassay and, except for ceftazidime, immunoassay for chemical activity. The bioassay was performed using a standardized Kirby-Bauer disc method. Significance was determined by ANOVA and, where the effect size was significant at the p < 0.05 level, the application of the paired t-test or the Wilcoxon signed rank test to the difference in activity between the first and last samples. RESULTS: Antibiotic concentration by immunoassay did not significantly deteriorate over 14 days for vancomycin or gentamicin when either room temperature or refrigerated samples were studied. By bioassay, gentamicin and ceftazidime, but not vancomycin, lost moderate but significant activity over 14 days when refrigerated bags were assayed (except for an insignificant decrement in gentamicin in the combined vancomycin and gentamicin bags). Bags stored at room temperature, in general, lost significant bioactivity over 14 days, but to levels where clinical efficacy would still be expected. The vancomycin bioassay performed on the combination bags demonstrated a remarkably enhanced bioactivity, presumably reflecting synergy with gentamicin. CONCLUSION: These data indicate that the study antibiotics admixed with peritoneal dialysis fluids retain stable chemical activity, whether refrigerated or kept at room temperature, for at least 14 days. A moderate decrement in bioactivity occurred for study antibiotics when stored either refrigerated or at room temperature over 14 days, although clinically significant levels were maintained. The clinical significance of a possible synergy between vancomycin and gentamicin is yet to be determined.