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

Vancomycin Dosing for Adults

For adults with normal renal function, administer vancomycin at 15-20 mg/kg (actual body weight) every 8-12 hours intravenously, with each dose infused over at least 60 minutes at a rate not exceeding 10 mg/min. 1, 2, 3

Standard Maintenance Dosing

• Weight-based dosing is mandatory: Calculate 15-20 mg/kg based on actual body weight, not fixed doses 1, 2
• The traditional fixed dose of 1 g every 12 hours is inadequate for most patients, particularly those weighing >70 kg or with obesity 1, 2
• Do not exceed 2 g per individual dose 1, 2
• Administer every 8-12 hours depending on infection severity and patient factors 1, 3
• Each dose must be infused over at least 60 minutes or at a maximum rate of 10 mg/min, whichever is longer 2, 3
• Use concentrations no greater than 5 mg/mL to minimize infusion-related reactions 2, 3

Loading Dose for Serious Infections

For critically ill patients with suspected or confirmed MRSA infection, sepsis, meningitis, pneumonia, endocarditis, or necrotizing fasciitis, administer a loading dose of 25-30 mg/kg (actual body weight). 1, 2

• The loading dose enables rapid achievement of therapeutic concentrations in seriously ill patients 1, 2
• Prolong the infusion time to 2 hours and consider premedication with an antihistamine to reduce red man syndrome risk 1, 2
• Critical point: The loading dose is NOT affected by renal function—only maintenance doses require adjustment for renal impairment 2
• Critically ill patients have expanded extracellular fluid volumes from resuscitation, necessitating higher loading doses 1

Therapeutic Monitoring

• Target trough concentrations of 15-20 μg/mL for serious infections (bacteremia, endocarditis, meningitis, pneumonia) 1, 2, 4
• Target trough concentrations of 10-15 μg/mL for non-severe infections 1
• Obtain trough levels at steady state, prior to the fourth or fifth dose 1
• The pharmacodynamic parameter predicting efficacy is AUC/MIC ratio >400 1, 2, 4
• Trough monitoring is mandatory for patients with renal dysfunction, obesity, or fluctuating volumes of distribution 1, 2

Common Pitfalls to Avoid

• Never use fixed 1 g doses without weight-based calculation—this results in underdosing in the majority of patients 1, 2
• Do not target high trough levels (15-20 μg/mL) for non-severe infections, as this unnecessarily increases nephrotoxicity risk 1, 2
• If vancomycin MIC is ≥2 μg/mL, switch to alternative therapies (daptomycin, linezolid, ceftaroline) as target AUC/MIC ratios are unachievable 1, 2
• Doses of at least 1 g every 8 hours are needed in critically ill trauma patients to achieve therapeutic troughs 5
• Nephrotoxicity risk increases with trough levels >15 mg/L, especially when combined with other nephrotoxic agents 1

Dosing Algorithm

1. Calculate weight-based dose: 15-20 mg/kg actual body weight 1, 2
2. Determine if loading dose needed: Use 25-30 mg/kg for serious/severe infections 1, 2
3. Select dosing interval: Every 8-12 hours based on infection severity and renal function 1, 3
4. Ensure proper infusion: Minimum 60 minutes, maximum 10 mg/min rate 2, 3
5. Monitor troughs: Obtain before 4th-5th dose, target 15-20 μg/mL for serious infections 1, 2