Comparison of intraocular penetration level of cefuzonam sodium and cefotiam after intravenous and subconjunctival injection

We investigated the intraocular penetration of a new Cephem type antibiotic: Cefuzonam sodium (CZON) following intravenous and subconjunctival injection. CZON was administered to 28 eyes in 26 patients by 1 g intravenous injection (IV) and to 11 eyes in 10 patients by 20 mg/0.2 ml subconjunctival injection (SCI). The penetration level of CZON by the IV method was from less than 0.0025-3.35 micrograms/ml into aqueous humor, from less than 0.0025-0.315 microgram/mg into iris tissue and 2.7-157.5 micrograms/ml into serum. The penetration level of CZON by the SCI method was from less than 0.0025-12.8 micrograms/ml into aqueous humor, from less than 0.0025-0.0426 microgram/mg into iris tissue and 1.03-18.5 micrograms/ml into serum. The penetration level of CZON into aqueous humor by SCI was higher than by IV administration. In comparison with the penetration level of CZON and Cefotiam (CTM), both aqueous humor and serum levels of CTM were higher than those of CZON. These results suggested that therapeutic levels in aqueous humor effective against gram-positive and gram-negative pathogens were achieved with the 1 g IV and 20 mg SCI of CZON. However levels effective against Staphylococcus epidermidis were only erratically attained.