Susceptible Infections

Use of ideal body weight (IBW) for determining the mg/kg/dose appears to be more accurate than on the basis of total body weight (TBW)

Infants: 2.5 mg/kg/dose IV/IM q8hr

Children and adolescents:: 2-2.5 mg/kg/dose IV/IM q8hr  

<30 weeks' gestation

• 0-28 days: 2.5 mg/kg/day IV/IM  
• >28 days: 3 mg/kg/day IV/IM

30-36 weeks' gestation

• 0-14 days: 3 mg/kg/day IV/IM  
• >14 days: 5 mg/kg/day IV/IM divided q12hr

>36 weeks' gestation

• 0-7 days: 5 mg/kg/day IV/IM divided q12hr  
• >7 days: 7.5 mg/kg/day IV/IM divided q8hr

Surgical Prophylaxis, Preoperative (Off-label use)

2.5 mg/kg IV/IM within 60 min piror to surgical incision or without antibiotics; procedure dependent  

Dose is based on actual body weight unless >20% above ideal body weight; then dosage requirement may best be estimated using a dosing weight of IBW + 0.4 (TBW- IBW)

Dosage Modifications

GFR>50 mL/min/1.73m²: No dosage adjustment necessary

GFR 30-50 mL/min/1.73m²: Administer q12-18hr

GFR 10-29 mL/min/1.73m²: Administer q18-24hr

GFR <10 mL/min/1.73m² Administer q48-72hr

Intermitent hemodialysis: 2 mg/kg/dose; redose as indicated by serum concentration

Peritoneal dialysis: 2 mg/kg/dose; redose as indicated by serum concentration

Continuous renal replacement therapy: 2-2.5 mg/kg/dose q12-24hr; monitor serum concentration  

Dosing Considerations

Monitor peak (4-12 mg/L) and trough (1-2 mg/L)

Monitor nephrotoxicity, neurotoxicity, and ototoxicity; assess at beginning of therapy and throughout

Individualization critical due to low therapeutic index

Use ideal body weight for mg/kg/dose, except in neonates (in whom actual body weight should be used)

Bacterial organisms causing susceptible infections

• Pseudomonas aeruginosa
• Proteus species (indole-positive and indole-negative)
• Escherichia coli
• Klebsiella-Enterobacter-Serratia species
• Citrobacter species
• Staphylococcus species (coagulase-positive and coagulase-negative)