Drug Interaction Report

MONITOR: Piperacillin may prolong the effects of nondepolarizing muscle relaxants. The mechanism is unknown, but small trials and case reports have provided data in support of an interaction between piperacillin and vecuronium. In contrast, a randomized controlled trial involving thirty patients undergoing abdominal operations reported no clinically important prolongation of vecuronium-induced muscle relaxation when piperacillin or cefoxitin was administered pre- or intra-operatively. The clinical significance and the extent to which other nondepolarizing muscle relaxants may interact remains unclear.

MANAGEMENT: Close observation for profound and prolonged respiratory depression and muscle weakness is recommended if these drugs must be used together.