What is the recommended dose of vancomycin for adults?

Vancomycin Dosing for Adults

For adults with normal renal function, the standard vancomycin dosage is 15-20 mg/kg every 8-12 hours, with a usual daily intravenous dose of 2 g divided either as 500 mg every 6 hours or 1 g every 12 hours. 1, 2

Standard Dosing Recommendations

Adults with Normal Renal Function

• Dose: 15-20 mg/kg/dose every 8-12 hours 1
• Usual daily IV dose: 2 g 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) to reduce the risk of infusion-related events 2

Special Populations and Considerations

Serious Infections

• For serious infections (bacteremia, endocarditis, osteomyelitis, meningitis, pneumonia, severe skin/soft tissue infections):
  • Target trough levels: 15-20 μg/mL 1
  • Consider loading dose: 25-30 mg/kg to rapidly achieve therapeutic levels 1

Renal Impairment

• Daily dose (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: 15 mg/kg loading dose, then adjust based on serum levels 2

Obese Patients

• Use actual body weight for initial dosage calculation 1
• Higher doses may be required in obese patients to achieve target concentrations 3
• Recent evidence suggests 35 mg/kg/day (maximum 5500 mg/day) for obese individuals without renal impairment 3

Therapeutic Monitoring

• Obtain vancomycin trough levels immediately before the fourth or fifth dose (at steady state) 1

• Target trough concentrations:

  • 15-20 μg/mL for serious MRSA infections 1
  • 10-15 μg/mL for mild-moderate skin and soft tissue infections 1

• Recent evidence suggests monitoring area under the curve (AUC) rather than trough concentrations may reduce nephrotoxicity while maintaining efficacy 4, 5

Administration Considerations

• Vancomycin should be infused over at least 60 minutes to reduce the risk of "red man syndrome" 1, 2
• Maximum concentration: 5 mg/mL (up to 10 mg/mL in patients requiring fluid restriction) 2
• Maximum infusion rate: 10 mg/min 2

Common Pitfalls and Caveats

1. Underdosing in critically ill patients: Patients with sepsis or septic shock may require higher doses (≥2 g every 8 hours) with creatinine clearance ≥80 mL/min/1.73m² to achieve therapeutic targets 6, 7

2. Nephrotoxicity risk: Higher trough concentrations (>15 μg/mL) are associated with increased nephrotoxicity risk. AUC-based dosing may reduce nephrotoxicity compared to trough-based dosing 4, 5

3. Incorrect weight-based calculations: Using ideal body weight instead of actual body weight in obese patients may lead to underdosing 1, 3

4. Inadequate loading doses: Failure to administer appropriate loading doses (25-30 mg/kg) in serious infections can delay achieving therapeutic concentrations 1, 7

5. Monitoring timing errors: Obtaining trough levels too early (before steady state) or at incorrect times may lead to inappropriate dose adjustments 1