drug dosing

  1. increased F due to a reduction in first-pass
    dihydrocodeine, propranolol, dextropropoxy
  2. decreased PPB uremia causing increase Vd
    pheny, valc, warfa, salicy, diazepa,, clorazepate
  3. decreased tissue binding due to compeptivee displacement by accumlation of uremic toxins causing a dec in Vd
    digoxin, dec by 30-50%
  4. increase in Vd due to increase in tbw
    ags, and vanco
  5. drugs metabolized to pharmacologically active metabolites and eliminated by kidney
    APAP, codeine, meperidine (CNS toxin), morphine, procainamide, propxy (CNS and cardiac toxin), sulfonamides, tramadol (contributes to CNS effect)
  6. fraction of drug elininated unchanged
    >=75% of concern, usually don't dose adjust until <50ml/min
  7. reasons for dose adjusting(4)
    • >=75%
    • drug or metab has narrow TI
    • kidney is major site of elim-insulin
    • sign decr in binding of narrow therpeutic range drug to plasma protein
  8. analgesics
    meperidine, morphine, ketoralac, tramadol
  9. abx need ad
    cepha, ags, vanco, ampici, imipenem, quiniolones, SMX/TMP, metronid
  10. antifungals adj
    flucon, flucytosine
  11. antidiabetics adj
    glyburide, met, insulin
  12. antivirals adj
  13. misc adj
    allopu, LMWH, metoclo, neurontin, pheny, statins
  14. quick estimation of CrCl
    (140-age)/Crx.85 if female
  15. rowland and tozer eq
    Q=1-[fe-(1-KF)], KF=crclf/crcln, fe=fraction excreted unchanged
  16. keep same dose, extend interval
    cmax and cmin are of concern, concentration dep, abs, antiarr, theoy, antiepill-may have prolonged period below min effective conc
  17. decrease dose, keep same interval
    same avg conc desired, antidep, antihyp, statins, chronic therapy
  18. exceptions for adjusting LD
    Vd small, LD smaller-dig, vd larger, ld larger-vanco and ags
  19. correction for hypoalbumineria for phenytoin
    <3.5, C adjusted=meas con/(.2 X meas alb)+.1
  20. correction for renal failure-pheny
    <15, C adjusted = meas conc/(0.1 X meas alb) + 0.1
  21. mW dialyz
    <500 D or <20000 high flux, less than <70%unchaged will pass
  22. Vd dialy
    • <1L/kg-most likely
    • 1-2-margin
    • >2-not removed
  23. redistribution phase length
    lithium-unkonw, ags-2 hr, vanco-4 hr
  24. commom medicqtions that are dialyzed ou5
    APAP, ASA, water sol vitamins, many abx, give antihyper after and warfarin after
Card Set
drug dosing