Two patients developed Coombs' positive hemolytic anemia while receiving cephalothin sodium therapy. An anticephalothin antibody was detected in the IgG fraction of sera and in the red blood cell (RBC) eluates in both patients. This complication of cephalothin therapy is rare, and must be differentiated from the positive Coombs' reaction seen in the majority of patients receiving cephalothin. In any patient receiving cephalothin, unexplained hemolysis must include a search for anticephalothin and antipenicillin antibodies on the RBC before the drug can be implicated in any hemolytic episode.
Gralnick HR, McGinniss M, Elton W, McCurdy P. Hemolytic Anemia Associated With Cephalothin. JAMA. 1971;217(9):1193-1197. doi:10.1001/jama.1971.03190090015004