What is the appropriate vancomycin dosage for osteomyelitis in a patient weighing 232 pounds?

From the Guidelines

Vancomycin dosage for osteomyelitis in a patient weighing 232 pounds should be 15-20 mg/kg/day every 8-12 hours.

Calculating the Dosage

To calculate the dosage, we need to first calculate the patient's weight in kilograms.

• Weight in pounds: 232 pounds
• Weight in kilograms: 232 pounds / 2.2 pounds/kilogram = 105.45 kilograms

Recommended Dosage

According to the guidelines 1, the recommended dosage of vancomycin for osteomyelitis is 15-20 mg/kg/day every 8-12 hours.

• Minimum dosage: 15 mg/kg/day * 105.45 kg = 1581.75 mg/day
• Maximum dosage: 20 mg/kg/day * 105.45 kg = 2109.00 mg/day

Administration

The dosage can be administered every 8-12 hours, which translates to:

• Minimum dosage: 1581.75 mg/day / 3 (for every 8 hours) = 527.25 mg every 8 hours
• Maximum dosage: 2109.00 mg/day / 3 (for every 8 hours) = 703.00 mg every 8 hours
• Minimum dosage: 1581.75 mg/day / 2 (for every 12 hours) = 790.88 mg every 12 hours
• Maximum dosage: 2109.00 mg/day / 2 (for every 12 hours) = 1054.50 mg every 12 hours It's essential to monitor the patient's renal function and adjust the dosage accordingly, as vancomycin is primarily excreted by the kidneys 1. Additionally, trough vancomycin monitoring is recommended for serious infections like osteomyelitis, especially in patients with renal dysfunction or fluctuating volumes of distribution 1. The guidelines also suggest that vancomycin trough concentrations of 15-20 μg/mL are recommended for serious infections like osteomyelitis 1. It's crucial to note that these guidelines are based on the patient's actual body weight, and weight-based dosing is particularly important in obese patients to avoid underdosing 1.

From the FDA Drug Label

DOSAGE AND ADMINISTRATION ... Patients with Normal Renal Function ... The usual daily intravenous dose is 2 g divided either as 500 mg every 6 hours or 1 g every 12 hours.

Other patient factors, such as age or obesity, may call for modification of the usual intravenous daily dose

The patient weighs 232 pounds, which is approximately 105 kg.

• The usual daily dose for patients with normal renal function is 2 g.
• Obesity may require modification of the dose, but the label does not provide specific guidance for dosing in obese patients. Given the lack of specific dosing recommendations for obese patients, a conservative approach would be to use the standard dosing regimen and monitor the patient's response and vancomycin serum concentrations closely. The appropriate vancomycin dosage for osteomyelitis in this patient would be 2 g per day, divided as 500 mg every 6 hours or 1 g every 12 hours, with close monitoring of serum concentrations 2.

From the Research

Vancomycin Dosage for Osteomyelitis

To determine the appropriate vancomycin dosage for osteomyelitis in a patient weighing 232 pounds, we need to consider the following factors:

• The patient's weight and the recommended dosage per kilogram of body weight
• The type of infusion method used (intermittent or continuous)
• The target serum concentration of vancomycin

Recommended Dosage

According to the study 3, a high dose vancomycin treatment (40 mg/kg/d) was compared to a standard dose treatment (20 mg/kg/d). For a patient weighing 232 pounds (approximately 105 kg), the high dose would be: 40 mg/kg/d x 105 kg = 4200 mg/d

The standard dose would be: 20 mg/kg/d x 105 kg = 2100 mg/d

Infusion Method

The study 4 compared intermittent vancomycin infusion (IVI) and continuous vancomycin infusion (CVI) in high-dose therapy of osteomyelitis. The results showed that CVI achieved target serum concentrations quicker and had fewer adverse drug reactions.

Target Serum Concentration

The study 4 aimed to achieve a target serum concentration of vancomycin of 20-25 mg/L. The study 3 found that the best outcome was achieved with high-dose continuous vancomycin infusion (HD-CVI), which provided an improved outcome with fewer adverse drug reactions.

Key Points

• High-dose vancomycin treatment (40 mg/kg/d) may be more effective than standard dose treatment (20 mg/kg/d) for osteomyelitis 3
• Continuous vancomycin infusion (CVI) may be preferred over intermittent vancomycin infusion (IVI) due to faster achievement of target serum concentrations and fewer adverse drug reactions 4
• The target serum concentration of vancomycin should be 20-25 mg/L 4