What is the recommended dose of vancomycin for adults with normal renal function?

Vancomycin Dosing for Adults with Normal Renal Function

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

Standard Dosing Algorithm

For Non-Severe Infections (e.g., uncomplicated cellulitis)

• Administer 1 g IV every 12 hours for non-obese patients with normal renal function 1, 2
• Trough monitoring is not required in this population 1, 2
• Each dose should be infused over at least 60 minutes, or at a rate no faster than 10 mg/min, whichever is longer 3

For Severe or Serious Infections (e.g., bacteremia, endocarditis, osteomyelitis, meningitis, hospital-acquired pneumonia)

• Use weight-based dosing: 15-20 mg/kg every 8-12 hours based on actual body weight 1, 2
• Consider a loading dose of 25-30 mg/kg (actual body weight) for critically ill patients to rapidly achieve therapeutic concentrations 2
• Target trough concentrations of 15-20 μg/mL 1, 2
• Obtain trough levels before the fourth or fifth dose to ensure steady-state monitoring 1, 2

Critical Dosing Considerations by Body Habitus

Obese Patients

• Always use actual body weight for dosing calculations 1, 2
• Conventional fixed dosing of 1 g every 12 hours results in subtherapeutic levels and treatment failure 1, 2
• Trough monitoring is mandatory in obese patients 2

Standard Weight Patients (Non-Obese)

• For a 70 kg patient with severe infection: 15-20 mg/kg = 1050-1400 mg per dose 2
• Round to practical doses (e.g., 1000-1500 mg) 4

Infusion Rate and Red Man Syndrome Prevention

• Infuse at no more than 10 mg/min or over at least 60 minutes, whichever is longer 3
• For doses exceeding 1 g, extend infusion time to 1.5-2 hours to minimize infusion-related adverse effects 1
• Consider premedication with antihistamines when administering loading doses 2
• Maximum concentration should not exceed 5 mg/mL (10 mg/mL may be used in fluid-restricted patients but increases infusion reaction risk) 3

Therapeutic Monitoring Strategy

When to Monitor

• Mandatory monitoring for: 2
  • Serious infections requiring trough targets of 15-20 μg/mL
  • Obese patients
  • Patients with fluctuating renal function
  • Prolonged therapy courses
• No monitoring needed for uncomplicated infections in non-obese patients with normal renal function receiving 1 g every 12 hours 1, 2

Target Concentrations

• Serious infections: Trough 15-20 μg/mL 1, 2
• Non-severe infections: Trough 10-15 μg/mL 2
• Pharmacodynamic target: AUC/MIC ratio >400 2, 5

Common Pitfalls to Avoid

• Do not use 1 g every 12 hours in obese patients without weight-based calculation—this consistently leads to underdosing 1, 2
• Do not use 1 g every 12 hours for critically ill trauma patients with severe infections—studies show this achieves trough levels of only 6.8 mg/L, far below the 15-20 mg/L target 6
• Do not target high trough levels (15-20 μg/mL) for non-severe infections—this unnecessarily increases nephrotoxicity risk 2
• Consider alternative agents if vancomycin MIC ≥2 μg/mL—target AUC/MIC ratios are not achievable with conventional dosing 2, 5

Practical Dosing Examples

Example 1: 80 kg patient with MRSA bacteremia

• Loading dose: 25 mg/kg × 80 kg = 2000 mg IV over 2 hours 2
• Maintenance: 15-20 mg/kg × 80 kg = 1200-1600 mg every 8-12 hours 2
• Practical regimen: 1500 mg IV every 12 hours 2
• Monitor trough before 4th dose, target 15-20 μg/mL 1, 2

Example 2: 70 kg patient with uncomplicated cellulitis

• 1000 mg IV every 12 hours 1, 2
• No trough monitoring required 1, 2
• Infuse over 60 minutes 3