1. Identify the peak concentrations for Gentamicin and Tobramycin based on diagnosis.
    • 2-4 mcg/ml: uncomplicated lower UTI
    • 4-5 mcg/ml: gram+ endocarditis (synergistic w/ penicillin)
    • 6-8 mcg/ml: gram- infections (ex: sepsis)
    • 8-10 mcg/ml: gram- pneumonia
    • 10-12 mcg/ml: gram- pneumonia in pt w/ cystic fibrosis
  2. What is the trough concentration of gentamicin and tobramycin?
    < 1-2 mcg/ml
  3. Identify the peak concentrations of Amikacin based on diagnosis.
    • 20-30 mcg/ml: gram- infections (ex: sepsis)
    • 25-35 mcg/ml: gram- pneumonia
  4. What is the trough concentration Amicakin?
    < 5-10 mcg/ml
  5. When should aminoglycoside peaks and troughs be drawn?
    Peak: 30-60 min after a 30 minute infusion; 15 min after the end of a 60 min infusion

    Trough: 30 min or less prior to next dose
  6. What are the adverse effects and toxicities associated with aminoglycosides?
    • Nephrotoxicity
    • Neurotoxicity
    • Ototoxicity
  7. Describe the effects of nephrotoxicity associated with aminoglycoside toxicity.
    • may occur w/in 4-5 days (usually takes 5-10 days)
    • highest risk w/ duration > 10 days
    • usually nonoliguric
    • reversible in most cases
    • similar risk w/ gent/tobra/amikacin
    • average incidence ~20% (range 0-56%)
    • risk factors: age, other dz states, other nephrotoxic drugs
  8. Describe the effects of neurotoxicity associated with aminoglycosides.
    • muscle twitching
    • numbness
    • seizures
    • tingling
  9. Describe the effects of ototoxicity associated with aminoglycosides.
    • clinical incidence 0.5-3%
    • damage to 8th cranial nerve
    • may be unilateral or bilateral
    • onset is variable
    • cochlear (auditory): loss of hearing, tinnitus, feeling of ear fullness; often irreversible
    • vestibular: vertigo, ataxia, nystagmus, dizziness, n/v, unsteadiness; often irreversible
  10. When should a loading dose of aminoglycosides be used?
    When CrCl is < 30 ml/min
  11. What patient weight should be used for CrCl, Vd and dose when dosing aminoglycoside?
    CrCl = TBW

    Vd = IBW

    Dose = IBW

    **Use Adjusted BW if patient is obese**
  12. What are the extended interval aminoglycoside dosing values for gentamicin/tobramycin and amikacin?
    Gentamicin/Tobramycin: 7mg/kg

    Amikacin: 15 mg/kg
  13. How should initial interval dosing of aminoglycosides be determined?
    • 1. Calculate weight based dose
    • 2. Creatinine clearance determines the dosing interval

    ex: > 60ml/min = q 24h dosing
Card Set