Tizanidine

Zanaflex

Muscle relaxant • Alpha-2 adrenergic agonist

QT RiskCNS DepressantHepatotoxic

Half-life

2.5 hours

Protein Binding

30%

Metabolized By

CYP1A2

External

Activates alpha-2 adrenergic receptors, reducing spinal motor neuron excitability

Drug Class

Muscle relaxant

Subclass

Alpha-2 adrenergic agonist

Zanaflex

Half-life

2.5 hours

Time for plasma concentration to decrease by 50%

Protein Binding

30%

Fraction bound to plasma proteins

Therapeutic Index

Wide

Margin between therapeutic and toxic doses