Sinemet

CLINICAL USE


Treatment of Parkinsonism

DOSE IN NORMAL RENAL FUNCTION

75–800 mg carbidopa daily in divided doses after meals

PHARMACOKINETICS

  • Molecular weight &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp :Carbidopa: 244.2, levodopa: 197.2
  • %Protein binding &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp :Carbidopa: 36, levodopa: 10–30
  • %Excreted unchanged in urine &nbsp &nbsp : Carbidopa: 30, levodopa: <1
  • Volume of distribution (L/kg) &nbsp &nbsp &nbsp :Carbidopa: no data, levodopa: 0.36–1.6
  • half-life – normal/ESRD (hrs)&nbsp &nbsp &nbsp :Carbidopa: 2–3, levodopa: 0.6–1.3/Unknown

    DOSE IN RENAL IMPAIRMENT

    GFR (mL/MIN)

  • 20 to 50 &nbsp &nbsp : Dose as in normal renal function
  • 10 to 20 &nbsp &nbsp : Dose as in normal renal function
  • <10 &nbsp &nbsp &nbsp &nbsp &nbsp : Dose as in normal renal function

    DOSE IN PATIENTS UNDERGOING RENAL REPLACEMENT THERAPIES

  • CAPD &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp:Unlikely to be dialysed. Dose as in normal renal function

  • HD &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp :Unlikely to be dialysed. Dose as in normal renal function
  • HDF/high flux &nbsp :Unknown dialysed. Dose as in normal renal function
  • CAV/VVHD &nbsp &nbsp &nbsp:Unknown dialysability. Dose as in normal renal function

    IMPORTANT DRUG INTERACTIONS

    Potentially hazardous interactions with other drugsAnaesthetics: risk of arrhythmias with volatile liquid anaesthetics such as halothaneAntidepressants: hypertensive crisis with MAOIs and linezolid (including moclobemide) – avoid for at least 2 weeks after stopping MAOIBupropion: increased risk of side effects of levodopaFerrous sulphate: reduces AUC of levodopa by 30–50%, clinically significant in some but not all patients

    ADMINISTRATION

    Reconstition

    Route

    Oral

    Rate of Administration

    Comments

    OTHER INFORMATION

    Can be used to treat restless legs syndrome May cause dark urine