MOXQUIN XG 5 ML eye drop is a sterile ophthalmic solution containing moxifloxacin hydrochloride and xanthan gum. 1 Moxifloxacin is a fourth-generation fluoroquinolone antibiotic that works by inhibiting bacterial DNA gyrase and topoisomerase IV, essential enzymes for bacterial DNA replication, transcription, 2 and repair, thereby treating bacterial eye infections. Xanthan gum is a viscosity-enhancing agent that helps to prolong the contact time of the medication with the eye surface for better efficacy. 3 This combination is indicated for the treatment of bacterial conjunctivitis caused by susceptible strains of bacteria. 4 The usual dosage is typically one drop in the affected eye(s) twice daily for 7 days. Common side effects may include eye irritation, dry eye, burning or stinging sensation, and blurred vision.