Not true about aztreonam ?

Ans. is 'd' i.e., Shows cross reactivity with other penicillins Aztreonam It belongs to monobactams group of 13-lactam antibiotics. It is active against gram negative organisms including pseudomonas, but has no activity against gram positive organisms or anaerobes fi-lactam antibiotic with aminoglycosides spectrum. It is the only fi-lactam antibiotic that lack cross-reactivity with other P-lactam antibiotics, permiting its used in patients allergic to penicillins or cephalosporins.