Moxifloxacin is a broad-spectrum antibiotic that is active against both Gram-positive and Gram-negative bacteria. It functions by inhibiting DNA gyrase, a type II topoisomerase, and topoisomerase IV,[44] enzymes necessary to separate bacterial DNA, thereby inhibiting cell replication. Moxifloxacin is not believed to be associated with clinically significant drug interactions due to inhibition or stimulation of hepatic metabolism. Thus, it should not, for the most part, require special clinical or laboratory monitoring to ensure its safety. However, there is an additive effect of moxifloxacin and drugs that prolong the QT interval, such as cisapride, erythromycin, antipsychotics, and tricyclic antidepressants. Therefore, moxifloxacin should be used with caution when given concurrently with such drugs. Moxifloxacin also has a potential for a serious drug interaction with NSAIDS.