Tizanidine
Tizanidine.JPG

CLINICAL USE

Spasticity associated with multiple sclerosis or spinal cord injury/disease

DOSE IN NORMAL RENAL FUNCTION

2–24 mg daily in up to 3–4 divided doses (depending on response)

PHARMACOKINETICS

  • Molecular weight                           : 290.2 (as hydrochloride)
  • %Protein binding                           : 30
  • %Excreted unchanged in urine     : <11
  • Volume of distribution (L/kg)       : 2.4
  • half-life – normal/ESRD (hrs)      : 2–4/Increased

    DOSE IN RENAL IMPAIRMENT

    GFR (mL/MIN)

    25–50 Dose as in normal renal function <25 Initial dose 2 mg once daily and slowly increase by 2 mg increments. Increase daily dose before increasing frequency of administration

    DOSE IN PATIENTS UNDERGOING RENAL REPLACEMENT THERAPIES

  • CAPD                : Unknown dialysability. Dose as in GFR<25 mL/min
  • HD                     : Unknown dialysability. Dose as in GFR<25 mL/min
  • HDF/high flux   : Unknown dialysability. Dose as in GFR<25 mL/min
  • CAV/VVHD      : Unknown dialysability. Dose as in GFR=25–50 mL/min

    IMPORTANT DRUG INTERACTIONS

    Potentially hazardous interactions with other drugs
  • Anti-arrhythmics: enhanced muscle relaxant effect with procainamide
  • Antibacterials: concentration increased by ciprofloxacin – avoid concomitant use Antihypertensives: enhanced hypotensive effect Oral contraceptives: clearance of tizanidine reduced by 50%

    ADMINISTRATION

    Reconstition

    Route

    Oral

    Rate of Administration

    Comments

    OTHER INFORMATION

    Pharmacokinetic data suggest that renal clearance in the elderly may be decreased by up to 3-fold May induce hypotension; therefore may potentiate the effect of antihypertensive drugs, including diuretics – exercise caution With beta-blockers or digoxin, may potentiate hypotension or bradycardia LFTs should be monitored monthly for the first 4 months Tizanidine undergoes rapid and extensive first pass metabolism. The metabolites (mainly inactive) constitute 70% of the administered dose and are excreted via the renal route



    See how to identify renal failure stages according to GFR calculation

    See how to diagnose irreversible renal disease

    Home

  • other drugs