What is the recommended dose of vancomycin for adults?

Recommended Vancomycin Dosing for Adults

For adults with normal renal function, vancomycin should be dosed at 15-20 mg/kg/dose (based on actual body weight) every 8-12 hours, not to exceed 2 g per dose. 1

Standard Dosing Regimen

• Normal renal function:

  • 2 g daily divided as either 500 mg every 6 hours or 1 g every 12 hours 2
  • Each dose should be administered at no more than 10 mg/min or over at least 60 minutes (whichever is longer) 2
  • Alternative dosing: 15-20 mg/kg/dose every 8-12 hours 1

• Loading dose:

  • 25-30 mg/kg (actual body weight) for serious infections like sepsis and septic shock to rapidly achieve therapeutic levels 1

Renal Adjustment

• For patients with impaired renal function, the daily vancomycin dose in mg should be approximately 15 times the glomerular filtration rate in mL/min 1, 2
• Initial dose should be no less than 15 mg/kg, even in patients with mild to moderate renal insufficiency 2
• For functionally anephric patients, an initial dose of 15 mg/kg followed by dose adjustment based on serum levels 2

Monitoring

• Obtain vancomycin trough levels immediately before the fourth dose (at steady state) 1
• Target trough concentrations:
  • 15-20 μg/mL for serious infections (bacteremia, endocarditis, osteomyelitis, meningitis, pneumonia) 1

  • 10 mg/L to prevent resistance 1

Special Populations

• Obese patients: Use actual body weight for initial dosing calculations with careful monitoring 1

  • Recent research suggests 35 mg/kg/day (maximum 5500 mg/day) for obese individuals to achieve target exposure 3

• Elderly patients: May require greater dosage reductions than expected due to decreased renal function 2

Administration Considerations

• Infusion-related events are related to both concentration and rate of administration 2
• Use concentrations of no more than 5 mg/mL (up to 10 mg/mL in patients needing fluid restriction) 2
• Infuse at rates no more than 10 mg/min to reduce risk of "red man syndrome" 1, 2

Clinical Pearls and Pitfalls

• Standard dosing of 1 g every 12 hours is often inadequate to achieve target trough concentrations of 15-20 mg/L, particularly in critically ill patients 4
• Doses of at least 1 g every 8 hours are typically needed to achieve therapeutic targets in critically ill patients 4
• Continuous infusion may be advantageous compared to intermittent infusion in some patients 5
• Nephrotoxicity risk increases with higher trough concentrations, occurring in approximately 4.5% of patients, typically after a median of 8 days of therapy 6

The most recent guidelines from the Infectious Diseases Society of America emphasize weight-based dosing rather than fixed dosing to achieve optimal therapeutic levels while minimizing toxicity 1.