What is the recommended dose of vancomycin (Vancomycin hydrochloride) for adults?

Vancomycin Dosing Recommendations for Adults

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

Standard Dosing Regimen

Initial Dosing

• Normal renal function:
  • 15-20 mg/kg (actual body weight) every 8-12 hours 1
  • Maximum: 2 g per dose 1, 2
  • For most uncomplicated skin/soft tissue infections: 1 g every 12 hours may be adequate 1

Loading Dose

• For serious infections (sepsis, meningitis, pneumonia, endocarditis):
  • Consider loading dose of 25-30 mg/kg (actual body weight) 1
  • Extend infusion time to 2 hours
  • Consider antihistamine premedication to reduce risk of red man syndrome 1

Administration

• Infusion concentration: ≤5 mg/mL 2
• Infusion rate: ≤10 mg/min or over at least 60 minutes (whichever is longer) 2
• For fluid-restricted patients: Concentrations up to 10 mg/mL may be used, but with increased risk of infusion-related events 2

Therapeutic Monitoring

Trough Monitoring

• Serious infections (bacteremia, endocarditis, osteomyelitis, meningitis, pneumonia, severe SSTI):

  • Target trough: 15-20 μg/mL 1
  • Obtain trough at steady state (before 4th or 5th dose) 1

• Mild-moderate infections with normal renal function and non-obese patients:

  • Trough monitoring not required for standard 1 g every 12 hours regimen 1

• Mandatory trough monitoring for:

  • Serious infections
  • Morbidly obese patients
  • Renal dysfunction (including dialysis patients)
  • Patients with fluctuating volume of distribution 1

Important Considerations

• Peak concentration monitoring is not recommended 1
• Trough concentrations are the most practical method to guide vancomycin dosing 1
• Recent evidence suggests AUC-based monitoring may reduce nephrotoxicity compared to trough-based monitoring 3

Special Populations

Obese Patients

• Use actual body weight for dosing calculations 1, 4
• Morbidly obese patients may require more frequent dosing (q8h instead of q12h) to maintain therapeutic levels 4
• Increased risk of nephrotoxicity requires careful monitoring 3

Renal Impairment

• Dosage adjustment required 2
• Approximate daily dose (mg) = 15 × glomerular filtration rate (mL/min) 2
• Initial dose should not be less than 15 mg/kg even with mild-moderate renal impairment 2

Clinical Scenarios

Serious MRSA Infections

• For isolates with vancomycin MIC <2 μg/mL:
  • Continue vancomycin if clinical response is adequate 1
• For isolates with vancomycin MIC >2 μg/mL (VISA or VRSA):
  • Switch to alternative agent 1

Common Pitfalls to Avoid

1. Underdosing in obesity: Using ideal body weight instead of actual body weight can lead to subtherapeutic levels 4
2. Inadequate dosing frequency: Standard 1 g q12h regimens often fail to achieve target troughs of 15-20 μg/mL for serious infections like pneumonia 5
3. Nephrotoxicity risk: Higher trough concentrations (>15 μg/mL) are associated with increased nephrotoxicity risk; consider AUC-based monitoring when available 3, 6
4. Delayed monitoring: Failure to check trough levels at steady state can lead to inaccurate dose adjustments 1
5. Inappropriate infusion rates: Rapid infusion increases risk of red man syndrome 2

Conclusion

Vancomycin dosing requires careful consideration of patient factors, infection severity, and appropriate monitoring. For most adult patients with normal renal function, 15-20 mg/kg every 8-12 hours with appropriate trough monitoring represents the standard of care for serious infections.