Antibiotics differ in their tendency to cause infusion phlebitis: a prospective observational study.

Intravenous administration of antibiotics is a known risk factor for infusion phlebitis. We have previously demonstrated differences in cell toxicity for 4 antibiotics. Clinical experience indicates that antibiotics differ in their tendency to cause phlebitis. The present study was done prospectively on 550 patients with 1386 peripheral venous catheters. The incidence of phlebitis was 18.5% with antibiotics and 8.8% without (odds ratio 2.34). Dicloxacillin (odds ratio 5.74) and erythromycin (odds ratio 5.33) had the greatest tendency to cause phlebitis in univariate, multivariate and Cox regression analyses. Benzylpenicillin, cefuroxime and cloxacillin were also associated with a greater risk of phlebitis, whereas ampicillin, imipenem/cilastatin, clindamycin, netilmicin and vancomycin were not. Other risk factors were the site of insertion and age 51-60 y. Medication with warfarin was found to be protective, but not with aspirin. Treatment with low molecular weight heparin reduced the risk of phlebitis, but the difference was not significant. With regard to when antibiotics were given, the day-specific risk increased between Days 1 and 2, but no further on subsequent days. The hypothesis that antibiotics differ in their tendency to cause phlebitis was confirmed.