Fentanyl

CLINICAL USE

Opioid analgesic:Short surgical procedures Ventilated patients Chronic intractable pain

DOSE IN NORMAL RENAL FUNCTION

IV injection: with spontaneous respiration: 50– —200 mcg, then 50 mcg as requiredwith assisted ventilation: 0.3–3.5 mg, —then 100–200 mcg as required

IV infusion

: with spontaneous respiration: —50–80 nanograms/kg/minute adjusted according to responsewith assisted ventilation: 10 mcg/kg —over 10 minutes, then 0.1–3 mcg/kg/minuteTopical (chronic pain): 12–300 mcg/hour, patches changed every 72 hoursLozenges: 200–800 mcg over 15 minutes repeated after 15 minutes if required; maximum 2 doses per pain episode and 4 doses daily

PHARMACOKINETICS

  • Molecular weight                           :336.5
  • %Protein binding                           :80–85
  • %Excreted unchanged in urine     : <7
  • Volume of distribution (L/kg)       :4
  • half-life – normal/ESRD (hrs)      :2–7/Possibly increased

    DOSE IN RENAL IMPAIRMENT

    GFR (mL/MIN)

  • 20 to 50     : Dose as in normal renal function Titrate according to response
  • 10 to 20     : 75% of normal dose. Titrate according to response
  • <10           : 50% of normal dose. Titrate according to response

    DOSE IN PATIENTS UNDERGOING RENAL REPLACEMENT THERAPIES

  • CAPD                :Not dialysed. Dose as in GFR <10 mL/min
  • HD                     :Not dialysed. Dose as in GFR <10 mL/min
  • HDF/high flux   :Not dialysed. Dose as in GFR <10 mL/min
  • CAV/VVHD      :Not dialysed. Dose as in GFR=10–20 mL/min

    IMPORTANT DRUG INTERACTIONS

    Potentially hazardous interactions with other drugs

  • Antidepressants: possible CNS excitation or depression (hypertension or hypotension) in patients also receiving MAOIs (including moclobemide) – avoid concomitant use; possibly increased sedative effects with tricyclics
  • Antivirals: concentration increased by ritonavirSodium oxybate: enhanced effect of sodium oxybate – avoid concomitant use

    ADMINISTRATION

    Reconstition

    _

    Route

    IV, IM, topically, oral

    Rate of Administration

    Comments

    Compatible with sodium chloride 0.9% and glucose 5%

    OTHER INFORMATION

    For short surgical procedures the degree of renal impairment is irrelevantFor other indications, renal impairment may have a moderate effect on the elimination of the drug; however, as fentanyl is titrated to response the usual dose and method of administration remains valid.

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