Tizanidine (Zanaflex) is a centrally acting a2-adrenergic agonist. It is used to treat the spasms, cramping, and tightness of muscles caused by medical problems such as multiple sclerosis, back pain, or certain injuries to the spine. It can come in a white pill with the markings cor 138 and 2 scores on the back that create an X.

it has also shown hypnotic/sedative/anxiolytic properties as a result of sedation(drowsiness).

Tizanidin