Double-blind comparison of phlebitis produced by cefazolin versus cephalothin.

In a double-blind study with each patient as his own control, 1 g of cefazolin and 2 g of cephalothin were administered intravenously every 6 h to 20 patients in opposite arms for a period of 48 h each. The degree of phlebitis was significantly more severe with cephalothin than with cefazolin (P < 0.05); however, neither the incidence of phlebitis nor the time of onset of phlebitis was significantly different between the two drugs.