Thrombocytopenia associated with moxalactam administration.

Thrombocytopenia associated with moxalactam disodium administration occurred in an elderly, debilitated, 84-year-old male. The patient presented with a decreased platelet count and prolongation of prothrombin time and partial thromboplastin time. Occult blood was found in the urine and stool, and generalized petechiae with ecchymoses were found over the entire body. The moxalactam was discontinued because of suspected drug-induced thrombocytopenia, and daily vitamin K therapy was instituted. By day 2 of vitamin K therapy, the platelet count had risen slightly, but the patient's condition did not improve. On day 3 of vitamin K therapy, the platelet count had decreased. There was a generalized worsening of the patient's medical condition, and he expired two days later. The use of moxalactam has been associated with thrombocytopenia. The possibility of hemorrhage consequent to the use of this antibiotic is clinically important.