How does obesity affect vancomycin dosing?
Vancomycin serum concentrations are impacted by increased clearance, increased volume of distribution, and a shorter terminal half-life of this drug in obese patients. In fact, some advocate for more frequent dosing of vancomycin in obese patients to mitigate toxicity and improve efficacy [11].
How does obesity affect drug dosing?
When lean body weight increases there will be a corresponding increase in drug clearance and an increased dose may be required. Commonly used weight-based drugs that may require dose adjustment and monitoring in obesity, and in particular morbid obesity, are listed in Table 2.
How are antibiotics dosed for obesity?
American consensus guidelines recommend that initial doses for all patients including the obese should be based on TBW and then adjusted based on SVCs (97). Most published data support the use of the Cockcroft-Gault equation with TBW to calculate CrCl and vancomycin clearance in non-obese patients.
What weight should I use for vancomycin?
The 2011 Infectious Diseases Society of America (IDSA) MRSA guidelines recommend that vancomycin be dosed at 15 to 20 mg/kg/dose (actual body weight) every 8 to 12 hours, not to exceed 2 g per dose, in patients with normal renal function.
How is vancomycin clearance calculated?
Clearance
- CLvanco (mL/min/kg) = ([CrCl × 0.0075] + 0.04)
- Vd = 0.47 L/kg. Vd was estimated using an adjusted body weight (ABW).
How should anesthetics be dosed in obese patients?
In general, lean body weight is the most appropriate dose for most anesthetic drugs, with the exception of NDMB, where ideal body weight may be more appropriate. Succinylcholine should be dosed to total body weight.
What drugs accumulate in fat?
Drugs that dissolve in water (water-soluble drugs), such as the antihypertensive drug atenolol, tend to stay within the blood and the fluid that surrounds cells (interstitial space). Drugs that dissolve in fat (fat-soluble drugs), such as the antianxiety drug clorazepate, tend to concentrate in fatty tissues.
Are antibiotics dosed by weight?
Whereas children’s antibiotic dosing is generally calculated according to body mass, for adults, no such system is in place, and for those drugs that do have body mass specific guidelines for dosing, adherence is “inadequate,” according to the authors.
What medications are weight based?
Physiological factors
- Enoxaparin. A standard dose of enoxaparin (Lovenox®; Sanofi-Aventis U.S. LLC, Bridgewater, NJ, USA) is frequently used for DVT prophylaxis, regardless of weight.
- Linezolid.
- Vancomycin.
- Paricalcitol.
- Warfarin.
- Isoniazid.
- Local anesthetic.
- Types of medication.
How do you calculate vancomycin infusion rate?
- Administration of vancomycin by continuous infusion.
- Loading dose.
- Dose (in mg) = Target concentration (in mg/L) x Volume of distribution (in L/kg)
Is vancomycin renally dosed?
Vancomycin is processed by the kidneys, and this treatment affects drug dosing. Factors to consider when dosing vancomycin in a dialysis patient include when the dose is given (how often, and whether it is before or after dialysis treatment), and the amount of time in between administration and dialysis treatments.
What is the normal range for vancomycin?
The therapeutic range of Vancomycin is between 10-20 microgram/milliliter. Its peak level is between 25-50 microgram/milliliter. Any level beyond this may cause toxicity signs and symptoms.
What are the trough levels of vancomycin?
Target ranges for serum vancomycin concentrations have changed over the years. Early authors suggested peak levels of 30 to 40 mg/l and trough levels of 5 to 10 mg/l, but current recommendations are that peak levels need not be measured and that trough levels of 10 to 15 mg/l or 15 to 20 mg/l,…
What is the loading dose of vancomycin?
While not recommended by the guidelines, many institutions will “cap” a loading dose at approximately 2000 to 3000 mg. This calculator, when providing a loading dose, will cap at 3000 mg. A vancomycin loading dose cap of 3000 mg represents a maximum weight of 120 kg for a dose of 25 mg/kg.
What is the volume of distribution of vancomycin?
The volume of distribution for vancomycin ranges between 0.5 and 1 L/kg. In clinical practice, an average value of 0.7 L/kg is often used; however, age and gender may also influence the distribution of vancomycin.