In vitro interaction between the penem FCE 22101 and ceftazidime

FCE 22101, a penem antimicrobial agent, was found to resist hydrolysis by bacterial beta-lactamases and to have a strong affinity for Type Ia enzymes. Like imipenem, FCE 22101 was shown to be capable of inducing resistance to a wide range of beta-lactam antibiotics. FCE 22101 antagonized the in vitro activity of ceftazidime against enteric bacilli that commonly produce inducible enzymes. This penem should not be combined with other beta-lactams for chemotherapeutic purposes.