Anesthesia Central is an all-in-one web and mobile solution for treating patients before, during, and after surgery. This collection of drug, procedures and test information is derived from Davis’s Drug, MGH Clinical Anesthesia Procedures, Pocket Guide to Diagnostic Tests, and MEDLINE Journals. Explore these free sample topics:
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First Things First (assess & treat for the following)
Pharmacokinetics is a description of the absorption, distribution, metabolism & excretion of a drug.
- Common pharmacokinetic abbreviations
- Ro: dose/(amount of time the drug infused over)
- Vd: volume of distribution
- ke: elimination rate constant
- T1/2: half-life
- ti: amount of time the drug infused over
- ∆t: time between the level should have been drawn and the drawn level
- τ: dosing interval
- Before you monitor a medication, you have to dose it. Below are listed some commonly used agents that require pharmacokinetic monitoring that need weight-based dosing.
- Aminoglycosides (Conventional Dosing)
Gentamicin and Tobramycin Dose
1 mg/kg (gentamicin only)
Urinary tract infection
Bacteremia/skin and soft tissue infection
- Aminoglycoside dosing weight: IBW + 0.4 (TBW - IBW)
- Ideal Body Weight (IBW) for men in kg: 50 + 2.3 (# of inches above 5 ft)
- Ideal Body Weight for women in kg: 45.5 + 2.3 (# of inches above 5 ft)
- Total Body Weight (TBW) in kg: Patient’s actual body weight
- Aminoglycoside dosing interval determination
- ke: 0.00293 x Creatinine Clearance + 0.014
- τ: ((ln (Goal Trough/Goal Peak)/ (-ke)) + ti
- Use 8, 12, or 24 hours.
- If >24 hours, dose intermittently based on levels.
- 15 mg/kg for most infections
- 20 mg/kg for meningitis or pneumonia
- Use TBW in most patients.
- Use Adjusted Body Weight (ABW) in obese patients
- ABC = IBW + 0.2 (TBW - IBW)
- Dosing Interval
- k: 0.00083 x Creatinine Clearance + 0.004
- τ: ((ln (Goal Trough/Goal Peak)/ (-k)) + ti
- Use 8, 12, 24, or 48 hours.
- If >48 hours, dose intermittently based on levels.
- Loading dose
- IV: 20 mg/kg
- PO: 20 mg/kg given in doses of 200-400 mg q2h
- Maintenance dose
- 5-6 mg/kg/day
- Do not give single dose >400 mg; divide it and give bid.
- Loading dose