Antibiotic-associated hypoprothrombinemia

An individual patient's vitamin K status and concomitant risk factors related to underlying disease determine the likelihood of hypoprothrombinemia and bleeding in patients requiring antibiotics. Patients at highest risk should be identified and monitored more aggressively or given prophylactic vitamin K. The propensity of various antibiotics to cause hypoprothrombinemia and bleeding differ substantially. Cefamandole, cefoperazone, and moxalactam appear to be most frequently implicated. Although the contribution of the NMTT moiety of specific antibiotics and the propensity to produce hypoprothrombinemia and bleeding remains controversial, in the setting of already compromised vitamin K status (or dietary intake and elimination or alteration of bowel flora) the NMTT moiety may be a contributing factor.

When antimicrobial regimens are compared in clinical trials, hypoprothrombinemia and bleeding should be considered potential adverse effects and appropriate prospective monitoring should be performed. Costs of monitoring for and management of this adverse effect should be considered in cost-benefit analysis.