Inhibition of peroxidase-catalyzed iodination by cephalosporins: Metallo-beta-lactamase-induced antithyroid activity of antibiotics.

Broad-spectrum antibiotics with heterocyclic side chains strongly inhibit peroxidase-catalyzed iodination in the presence of metallo-beta-lactamase. This suggests that antibiotic resistance due to hydrolysis of the beta-lactam ring in antibiotics would have negative effects on thyroid activity.