CLINICAL USE

Treatment of schizophrenia

DOSE IN NORMAL RENAL FUNCTION

25–100 mg 3 times a day

PHARMACOKINETICS

  • Molecular weight &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp : 331.9
  • %Protein binding &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp : 97
  • %Excreted unchanged in urine &nbsp &nbsp : <0.1 (40% as metabolites)
  • Volume of distribution (L/kg) &nbsp &nbsp &nbsp : 50–168
  • half-life – normal/ESRD (hrs)&nbsp &nbsp &nbsp : 14/Increased

    DOSE IN RENAL IMPAIRMENT

    GFR (mL/MIN)

  • 20 to 50 &nbsp &nbsp : 25 mg twice daily increasing to 75 mg twice daily
  • 10 to 20 &nbsp &nbsp : 25 mg twice daily increasing to 75 mg twice daily
  • <10 &nbsp &nbsp &nbsp &nbsp &nbsp : 25 mg twice daily increasing to 75 mg twice daily

    DOSE IN PATIENTS UNDERGOING RENAL REPLACEMENT THERAPIES

  • CAPD &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp: Unknown dialysability. Dose as GFR <10 mL/min

  • HD &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp : Unknown dialysability. Dose as GFR <10 mL/min
  • HDF/high flux &nbsp : Unknown dialysability. Dose as GFR <10 mL/min
  • CAV/VVHD &nbsp &nbsp &nbsp: Unknown dialysability. Dose as GFR 10 to 20 mL/min

    IMPORTANT DRUG INTERACTIONS

    Potentially hazardous interactions with other drugs
  • Anaesthetics: enhanced hypotensive effect
  • Analgesics: increased risk of convulsions with tramadol; enhanced hypotensive and sedative effects with opioids
  • Antidepressants: concentration increased by fluoxetine; concentration of tricyclics possibly increased
  • Anti-epileptics: antagonism, as convulsive threshold lowered
  • Antimalarials: avoid concomitant use with artemether/lumefantrine
  • Antivirals: concentration possibly increased by ritonavir Anxiolytics and hypnotics: enhanced sedative effects; concentration increased by diazepam
  • Sibutramine: increased risk of CNS toxicity – avoid concomitant use

    ADMINISTRATION

    Reconstition

    Route

    Oral

    Rate of Administration

    Comments

    OTHER INFORMATION

    Do not use if there is a history of nephrolithiasis Occasionally can increase creatinine levels Undergoes extensive first pass metabolism .