Brand Name : MYOLAX
Generic Name : Tizanidine
Preparations : 2 mg / 4 mg Tablets
Pharmacological Category : Muscle Relaxant (Centrally Acting α2 Adrenergic Agonist)

Mechanism of Action (MOA)
MYOLAX (Tizanidine) is a central α2-adrenergic agonist structurally related to clonidine. MYOLAX acts mainly at spinal and supraspinal levels to inhibit excitatory interneurones to release excitatory neurotransmitters.
MYOLAX may facilitate the inhibitory neurotransmitter, glycine as well.


  • Absorption : Well absorbed from the gastrointestinal tract
  • Bioavailability : Approximately 40%
  • Protein Binding : 30%
  • Metabolism : Liver
  • Elimination Half-life : 2 to 4 hours
  • Excretion : Urine (primarily)

Indications and Dosage

  • Symptomatic Relief of Spasticity associated with Multiple Sclerosis or with Spinal Cord Injury or Disease : One tablet of MYOLAX 4 mg every 6 to 8 hours as needed (no more than 3 doses in 24 hours) then increase by MYOLAX 2 to 4 mg per day to optimum effect; maximum dose: MYOLAX 36 mg per day.
  • Painful Muscle Spasms : MYOLAX 2 to 4 mg three times daily

Side Effects
SEEN : Drowsiness, dry mouth, fatigue, dizziness or vertigo, muscle pain and weakness, insomnia, anxiety, headache, bradycardia, nausea, gastrointestinal disturbances, hypotension, increased liver enzymes
RARE : Hallucination, acute hepatitis

Hypersensitivity to tizanidine, coadministration of ciprofloxacin or fluvoxamine or other potent CYP1A2 inhibitors

Warnings / Precautions

  • Potential for hypotension; monitor in patients receiving concurrent antihypertensive therapy
  • Caution in hepatic or the renal impairment, in women taking oral contraceptive pills.
  • Hepatotoxicity may occur; monitor aminotransferases prior to and during use.
  • Can cause sedation; additive sedation with alcohol and other CNS depressants
  • Visual hallucinations may occur.

Drug Interactions

  • Alcohol or other CNS depressants enhances the CNS effects of tizanidine.
  • Bradycardia is enhanced when concomitantly used with beta blockers or digoxin.
  • Additive hypotensive effect is seen when used with antihypertensive therapy.
  • Ciprofloxacin increases the plasma concentration of tizanidine thereby potentiating its hypotensive and sedative effects.
  • Fluvoxamine increases peak plasma concentrations and half-life elimination of tizanidine.
  • Severe hypotension occurs when tizanidine is concomitantly used with antihypertensives including lisinopril.
  • Oral contraceptives increases peak plasma concentration of tizanidine.
  • Tizanidine increases serum concentration of phenytoin.

Pregnancy Category : C

MYOLAX 2 mg : A box of 10 strips, each strip of 10 tablets
MYOLAX 4 mg : A box of 10 strips, each strip of 10 tablets