Moxalactam retinal toxicity

D. R. Fett, C. A. Silverman and M. O. Yoshizumi

Moxalactam disodium is a new third-generation semisynthetic, broad-spectrum, cephalosporin-like antibiotic for parenteral administration. Topical, subconjunctival, and intravenous administration provide poor concentration in the vitreous. To determine its toxicity in intravitreal administration, we injected comparative doses directly into the vitreous cavity of 21 rabbits. With doses of 1.25 mg or less there was no toxic damage to the retina. With a dose of 2.5 mg, early degeneration of photoreceptors was seen after three months. With higher doses (5 and 10 mg) there were major histopathologic and electroretinographic changes. These results suggest the feasibility of employing moxalactam in the treatment of acute, severe, fulminant bacterial endophthalmitis.