Clinical Efficacy And Pharmacokinetics (Pk) Of Moxalactam (Mlm) In Pediatric Skeletal Infections

The clinical efficacy and PK of the new β-lactam antibiotic, MLM, was investigated in 8 pediatric patients (8 wks.-16 yrs.) with skeletal infections. All patients received 150 mg/k/day IV in 3 divided doses for 1-4 weeks. Five children had osteomyelitis 3 with S. aureus, 1 with Serratia spp., and 1 with K. pneumoniae. Two had purulent synovial fluid without recovery of an organism. One had both osteomyelitis and septic arthritis due to S. aureus. All children demonstrated clinical improvement within 48 hrs. of the initiation of therapy. No drug-related toxicity was noted. In all cases, cultures at the termination of therapy were sterile. Ultimately, all had normal musculoskeletal function. After the initial dose and again after 3-5 days of therapy the PK of MLM were determined. A new, HPLC technique was used to measure serum concentrations. No difference in PK parameters was observed at the two time intervals. Mean peak serum concentrations were 235±48 μg/ml and exceeded the MIC's of the separate organisms for at least 3 hrs. No drug accumulation occurred during continuous therapy. The t½β was 100±31 min. and was independent of patient age. The apparent volume of distribution was ~0.45 L/kg suggesting good tissue penetration. We conclude that MLM is a safe, effective antimicrobial agent for the treatment of skeletal infections in childhood.