What is the treatment regimen for vancomycin?

Vancomycin Treatment Regimen

For adult patients with normal renal function, vancomycin should be dosed at 15-20 mg/kg (based on actual body weight) every 8-12 hours by intermittent intravenous infusion, with trough levels maintained at 15-20 mg/L for serious infections such as bacteremia, endocarditis, osteomyelitis, meningitis, and pneumonia. 1

Initial Dosing Strategy

• Calculate the initial dose using actual body weight (including obese patients) at 15-20 mg/kg per dose 1
• Administer by intermittent infusion over at least 60 minutes to avoid "red neck syndrome" (infusion-related erythema and hypotension) 2
• Standard dosing interval is every 12 hours for patients with creatinine clearance >50 mL/min 3
• Consider a loading dose of 25-30 mg/kg for critically ill patients with serious infections (bacteremia, endocarditis, pneumonia) to rapidly achieve therapeutic levels 1, 3

Therapeutic Drug Monitoring

When to Monitor

• Obtain the first trough level before the fourth dose to ensure steady-state conditions have been reached 1, 4
• Trough monitoring is mandatory for:
  • Serious infections (bacteremia, endocarditis, osteomyelitis, meningitis, pneumonia, severe skin/soft tissue infections) 1, 4
  • Morbidly obese patients 1, 4
  • Renal dysfunction or dialysis patients 1, 4
  • Fluctuating volumes of distribution 1, 4
  • Treatment duration >7 days 4

Target Trough Levels

• For serious MRSA infections: 15-20 mg/L to achieve an AUC/MIC ratio ≥400 1, 4, 3
• For uncomplicated skin/soft tissue infections in patients with normal renal function: traditional doses of 1 g every 12 hours are adequate and trough monitoring is not required 1
• Minimum trough of ≥10 mg/L should always be maintained to prevent development of resistance 1

Critical Pitfall: Peak Level Monitoring

Do not monitor peak levels—trough concentrations are the most accurate and practical method for vancomycin monitoring 1, 4. Peak level monitoring provides limited clinical value and is not recommended.

Dose Adjustment Based on Renal Function

Normal Renal Function (CrCl >50 mL/min)

• 15-20 mg/kg every 8-12 hours 3

Moderate Renal Impairment (CrCl 10-50 mL/min)

• 15-20 mg/kg every 24 hours with extended interval 3

Severe Renal Impairment (CrCl <10 mL/min)

• 15-20 mg/kg every 24-36 hours 3

Augmented Renal Clearance (CrCl >130 mL/min)

• 15 mg/kg every 8 hours achieves therapeutic AUC/MIC >400 in 82% of patients, compared to only 46% with every 12-hour dosing 5

Management of Elevated Trough Levels

If trough level exceeds 20 mg/L:

• Hold the next scheduled dose immediately 4
• Recheck trough level before administering subsequent doses 4
• Once level decreases to 15-20 mg/L, resume at reduced dose (approximately 15-20% reduction) or extend the dosing interval 4, 3
• Monitor serum creatinine closely for nephrotoxicity (defined as ≥0.5 mg/dL increase or 150% increase from baseline) 4, 3

Sustained trough concentrations >20 μg/mL significantly increase nephrotoxicity risk 4, 3

When NOT to Use Vancomycin

Do not use vancomycin when the organism's MIC is ≥2 mg/L (VISA/VRSA), as target AUC/MIC ratios are not achievable with conventional dosing—switch to alternative therapy 1, 4

Continuous Infusion: Not Recommended

Continuous infusion vancomycin regimens are not recommended as they do not substantially improve patient outcomes compared with intermittent dosing 1. Time above MIC is not the primary predictor of efficacy; the AUC/MIC ratio is the key pharmacodynamic parameter 1.

Special Clinical Scenarios

Chronic Kidney Disease

• Higher risk of nephrotoxicity, especially with trough levels >20 mg/L 3
• Avoid concomitant nephrotoxic agents when possible 4, 3
• Monitor serum creatinine at least twice weekly during treatment 3

Oral Vancomycin

• Reserved exclusively for Clostridioides difficile colitis (antibiotic-associated colitis) 6, 2
• Oral vancomycin is not absorbed systemically and cannot be used for systemic infections 6