1/18
Let’s talk vancomycin and the kidney.🧪
A 65 y/o woman on week 4 of IV vancomycin for ankle osteomyelitis presents with AKI (Cr 6.32mg/dL) and elevated vancomycin level (136 mg/dL).
What’s to blame?
#tweetorial #MedTwitter #Nephtwitter #FOAMed #TwitterRx @TheSkeletonKG
Let’s talk vancomycin and the kidney.🧪
A 65 y/o woman on week 4 of IV vancomycin for ankle osteomyelitis presents with AKI (Cr 6.32mg/dL) and elevated vancomycin level (136 mg/dL).
What’s to blame?
#tweetorial #MedTwitter #Nephtwitter #FOAMed #TwitterRx @TheSkeletonKG
2/18
Vancomycin nephrotoxicity is a challenging diagnosis because elevated vanc levels may be the cause and/or the effect of acute kidney injury.
Vanc nephrotoxicity is a diagnosis of exclusion based on:
◼️AKI
◼️Elevated vanc level
◼️No more likely explanation
Vancomycin nephrotoxicity is a challenging diagnosis because elevated vanc levels may be the cause and/or the effect of acute kidney injury.
Vanc nephrotoxicity is a diagnosis of exclusion based on:
◼️AKI
◼️Elevated vanc level
◼️No more likely explanation
3/18
The original vancomycin formulation earned the nickname Mississippi Mud (‘Sippi Mud for the locals) due to its muddy color and many nephrotoxins 🐷🐷🐷
The modern vancomycin formulation is 95% pure, but is associated with 2.45 relative risk of AKI
pubmed.gov
The original vancomycin formulation earned the nickname Mississippi Mud (‘Sippi Mud for the locals) due to its muddy color and many nephrotoxins 🐷🐷🐷
The modern vancomycin formulation is 95% pure, but is associated with 2.45 relative risk of AKI
pubmed.gov
4/18
Above what vancomycin concentration do you consider nephrotoxicity? 🎚️🎚️🎚️
Above what vancomycin concentration do you consider nephrotoxicity? 🎚️🎚️🎚️
5/18
There is no specific vancomycin concentration that causes nephrotoxicity.
Nevertheless, vancomycin nephrotoxicity is associated with:
⚠️higher vanc trough (>15mg/L)
⚠️greater daily dosage (>4g/d)
⚠️longer tx duration (>7 days)
pubmed.gov
There is no specific vancomycin concentration that causes nephrotoxicity.
Nevertheless, vancomycin nephrotoxicity is associated with:
⚠️higher vanc trough (>15mg/L)
⚠️greater daily dosage (>4g/d)
⚠️longer tx duration (>7 days)
pubmed.gov
6/18
Which of the patient’s comorbidities is likely a risk factor for vancomycin nephrotoxicity?☠️☠️☠️
Which of the patient’s comorbidities is likely a risk factor for vancomycin nephrotoxicity?☠️☠️☠️
7/18
Obesity is considered a risk factor for vancomycin nephrotoxicity because vancomycin dosing uses ‘actual body weight.’
👉 higher actual body weight
👉 more volume of distribution
👉 require higher Vanc dose
👉 more nephrotoxicity risk
Obesity is considered a risk factor for vancomycin nephrotoxicity because vancomycin dosing uses ‘actual body weight.’
👉 higher actual body weight
👉 more volume of distribution
👉 require higher Vanc dose
👉 more nephrotoxicity risk
8/18
🗝️🗝️🗝️
A key concept for safe and effective vanc dosing is:
A U C = Area Under the Curve
Vancomycin pharmacokinetics/pharmacodynamics are dependent on both “time” and “concentration,” which together are conceptualized as “AUC”
🗝️🗝️🗝️
A key concept for safe and effective vanc dosing is:
A U C = Area Under the Curve
Vancomycin pharmacokinetics/pharmacodynamics are dependent on both “time” and “concentration,” which together are conceptualized as “AUC”
9/18
AUC = Area Under the Curve of drug concentration over time.
How can we estimate the AUC ?📏📏📏
AUC = Area Under the Curve of drug concentration over time.
How can we estimate the AUC ?📏📏📏
10/18
Guidelines recommend Bayesian computer software to guide vanc dosing based on predicted AUC
Manual pharmacokinetic calculations of AUC are too cumbersome
Sure, you could draw vanc levels every 5 minutes to plot AUC, but please don’t. Ouch!💉💉💉
idsociety.org
Guidelines recommend Bayesian computer software to guide vanc dosing based on predicted AUC
Manual pharmacokinetic calculations of AUC are too cumbersome
Sure, you could draw vanc levels every 5 minutes to plot AUC, but please don’t. Ouch!💉💉💉
idsociety.org
11/18
⛰️⛰️⛰️
Vanc trough dosing is another dosing method
Vanc trough level is obtained prior to 4th dose in steady-state
Goal trough 15-20 mg/L for serious MRSA infxns (blood, CNS, bone, lung)
Trough-only dosing is no longer recommended in guideline, but remains widely used!
⛰️⛰️⛰️
Vanc trough dosing is another dosing method
Vanc trough level is obtained prior to 4th dose in steady-state
Goal trough 15-20 mg/L for serious MRSA infxns (blood, CNS, bone, lung)
Trough-only dosing is no longer recommended in guideline, but remains widely used!
12/18
AUC-guided vanc dosing may pose less risk of nephrotoxicity than trough-only vanc dosing.
pubmed.ncbi.nlm.nih.gov
How do you dose vancomycin at your institution???
AUC-guided vanc dosing may pose less risk of nephrotoxicity than trough-only vanc dosing.
pubmed.ncbi.nlm.nih.gov
How do you dose vancomycin at your institution???
13/18
Back to our patient — suspected vancomycin nephrotoxicity.
What’s your first move?
Back to our patient — suspected vancomycin nephrotoxicity.
What’s your first move?
14/18
Correct! Vancomycin nephrotoxicity usually improves with drug cessation and supportive care. In this case, kidney function worsened and hemodialysis was required.
How much will the vancomycin levels decrease after 1 session of hemodialysis?
Correct! Vancomycin nephrotoxicity usually improves with drug cessation and supportive care. In this case, kidney function worsened and hemodialysis was required.
How much will the vancomycin levels decrease after 1 session of hemodialysis?
15/18
⛽Vancomycin levels decrease ~30-40% after 1 session dialysis
⛽Elevated vancomycin levels are not an indication for dialysis, per se
⛽Instead, refractory kidney failure related to vancomycin may prompt other indications for dialysis (AEIOU)
⛽Vancomycin levels decrease ~30-40% after 1 session dialysis
⛽Elevated vancomycin levels are not an indication for dialysis, per se
⛽Instead, refractory kidney failure related to vancomycin may prompt other indications for dialysis (AEIOU)
16/18
After a comprehensive workup to rule out other causes of AKI, this case of vancomycin nephrotoxicity was clear as Mississippi Mud. This was a severe case with protracted recovery. Fortunately, after 8 wks our patient recovered kidney function and dc'd hemodialysis.
After a comprehensive workup to rule out other causes of AKI, this case of vancomycin nephrotoxicity was clear as Mississippi Mud. This was a severe case with protracted recovery. Fortunately, after 8 wks our patient recovered kidney function and dc'd hemodialysis.
17/18
In summary:
1️⃣ Vancomycin is associated with nephrotoxicity
2️⃣ Elevated vanc levels alone do not make the diagnosis of nephrotoxicity; consider other causes of AKI
3️⃣ AUC-guided vanc dosing is preferred over trough-only dosing
In summary:
1️⃣ Vancomycin is associated with nephrotoxicity
2️⃣ Elevated vanc levels alone do not make the diagnosis of nephrotoxicity; consider other causes of AKI
3️⃣ AUC-guided vanc dosing is preferred over trough-only dosing
18/18
Check out the fantastic visual abstract and blog post:
renalfellow.org
Special thank you to these great people, among many others! @SaiAchi1 @cdchu @kidney_boy @DTomacruzMD @SaynaNorouzi
@kkalra_22 @jamiekwillows @NephroGuy @Nephro_Sparks @Tiff_Caza @AnnaGaddy
Check out the fantastic visual abstract and blog post:
renalfellow.org
Special thank you to these great people, among many others! @SaiAchi1 @cdchu @kidney_boy @DTomacruzMD @SaynaNorouzi
@kkalra_22 @jamiekwillows @NephroGuy @Nephro_Sparks @Tiff_Caza @AnnaGaddy
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