Tizanidine (Molecule of the Month for August 2009)
Tizanidine ) is a drug that is used as a muscle relaxant. It is a centrally acting α-2 adrenergic agonist. It is used to treat the spasms, cramping, and tightness of muscles caused by medical problems such as multiple sclerosis, spastic diplegia, back pain, or certain other injuries to the spine or central nervous system. It is also prescribed off-label for migraine headaches, as a sleep aid, and as an anticonvulsant. It is also prescribed for some symptoms of fibromyalgia.
Tizanidine may cause hypotension, so caution is advised when it is used in patients who have a history of orthostatic hypotension. Tizanidine use occasionally causes drug induced liver injury. In controlled clinical studies, approximately 5% of patients treated with Zanaflex had elevations of liver function tests (ALT, AST)
If therapy needs to be discontinued, especially in patients who have been receiving high doses for long periods, the dose should be decreased slowly to minimize the risk of withdrawal and rebound hypertension, tachycardia, and hypertonia.
Formal Chemical Name (IUPAC)
Update by Karl Harrison
(Molecule of the Month for August 2009 )