Vancomycin/Aminoglycoside Kinetics - Block 1 Flashcards
Round vanc doses to the nearest ___?
250 mg
What should the final concentration of vanc be?
50mg/mL: 500mg, 750mg, 1g, 1.25g, and 1.5g in SWFI
100 mg/mL: 5 g or 10 g in SWFI
Further dilutd in D5W or NS -> ≤5 mg/mL
What is the infusion rate of vanc?
≥30 minutes for every 500 mg -> 1g/hr
Indication for vanc?
1st line for moderate-severe MRSA
ADR of vanc?
Ototoxicity, nephrotoxicity, red man syndrome
What is the LD of vanc?
Crit ill or severe infection: 20-35 mg/kg of ABW
* don’t exceed 3 g
What is considered severe infection?
- Bacteremia
- Osteomyelitis
- Endocarditis
- Meningitis
- HAp
How do you prevent vanc resistance?
- Avoid troughs less than <10mcg/mL
Trough goal of vanc?
Crit ill or severe infection: 15-20 mcg/mL
Normal: 10-15 mcg/mL
Goal AUC/MIC for vanc?
400-600
MRSA resistance in AUC/MIC <400
What is the maintence dose of vanc?
Base on weight and target trough:
* 10-15 mg/kg or 15-20mg/kg
How do you determine vanc dose frequnecy?
Ke = 0.00117 x CrCl + 0.003 (will be given on the test)
T1/2 = 0.693/Ke
Dosing interval = T1/2 x 1.5
* Round to either Q8, Q12, Q24, Q48
When do you order a vanc trough level?
Order trough prior to the 4th dose in dose frequency < Q24h
How do you dose vanc in AKI
Pulse dosing or dose by levels:
* Give a dose and check a random level
* Give 10 – 20 mg/kg
* Your level should be in your “trough goal range” before giving another dose
What is the definition of AKI?
- 1.5x baseline sCr within 7 days
- SCr increase at least 0.3 mg/dL in 48H
- UO <0.5 mL/kg/h for at least 6H
How should you adjust vanc based on trough?
Trough at goal: no changes
Trough below goal: Increase dose or shorten the frequency
Trough above goal: Decrease dose or extend the frequency
What is thevanc dosing in dialysis?
- LD: 20-25 mg/kg
- Set target trough lvel
- Order random level (6 hrs after HD)
- Adjust the dose based on the level & utilize the facility protocol
Vanc dosing for CVVH?
- Loading dose of 15-25 mg/kg
- Maintenance dosing of 10-15 mg/kg every 24-48 hours OR 1000 mg every 48 hours
- Obtain trough level prior to 2nd maintenance dose
- Adjust dose accordingly
Vanc dosing for CVVHD?
- Loading dose of 15-25 mg/kg
- Maintenance dosing of 10-15 mg/kg every 24 hours OR 1000 mg every 24 hours
- Obtain trough level prior to 3rd maintenance dose
- Adjust dose accordingly
Infusion rates of AG?
Gentamicin: 30-120 minutes
Tobramycin: 20-60 min, higher doses over 60 min, flush line with saline before and after admin
Amikacin: 30-60 minutes
ADRof AG?
Nephrotox and ototoxicity
Who should use extended interval dosing?
All patients with G- infections
Who uses traditional dosing of AG?
- Pregnant, postpartum
- Burns
- Ascites
- Dialysis, CrCl <30
- Synergic dosing
How do we dose AG?
- Determine IBW
- Compare with ABW
- AG distribution decreases in obeses
What is the initial dosing for extended interval?
- Dose
- Draw random level 6-14 hrs after dose
- Plot level on nomogram to determine frequncy
- If dosing amikacin, cut level in 1/2 before plotting
- If level/time falls on the line, move UP
What is the peak AG for extended interval?
Tobra and gent: 15-20 mcg/mL
Amikacin: 40-60 mcg/mL
What is the trough AG for extended interval?
Tobra and gent: ≤ 1 mcg/mL
Amikacin: target at 1 to 2 mcg/mL
How should you adjust AG in extended?
If the trough is too high, adjust the time
Plug in the nomogram – adjust the dose
How do ou dose traditional AG dosing? Target?
How do you calculate traditinal dosing interval?
Vd: 0.3 L/kg
Ke: 0.003 x CrCl + 0.01 (will be given)
T1/2: 0.693/Ke
Dosing interval: T1/2 x 3
* Round to nearest 8, 12, 24, 36, 48 hrs
When do you draw ss levels for traditional dosing?
Trough: 30 min prior to infusion
Peak: 30 min after infusion completed
How do you adjust AG based on trad peak levels
Adjust the DOSE
* If at goal: no change
* If high: decrease dose
* If low: increase dose
How do you adjust AG based on trad trough levels?
Adjust the FREQUENCY:
* If at goal: no change
* If high: decrease frequency
* If low: increase frequency
