To the Editor.—Cefotetan disodium, like moxalactam, cefoperazone, and cefamandole, contains an N-methylthiotetrazole (MTT) side chain that has been associated with hypoprothrombinemia and bleeding diathesis. Previously, cefotetan has been implicated in hypoprothrombinemia, without clinical bleeding, in patients with phytonadione (vitamin K1) deficiency.1 Two case reports of hypoprothrombinemia in surgical patients, with hemorrhage occurring in one patient, treated with cefotetan, are described.
Report of Cases.—Case 1.—An 86-year-old woman with a medical history significant for hypertension and kidney stones presented with pain in the right lower quadrant. Laboratory analysis revealed a hematocrit of 0.36 (36%), a white blood cell count of 21 × 109/L (21 × 103/mm3) (neutrophils, 0.90 [90%], band cells, 0.03 [3%]), and prothrombin and partial thromboplastin times of 13.8 s and 26 s, respectively. The coagulation values were within normal limits for Hartford (Conn) Hospital. An upright abdominal roentgenogram showed