Muscle Relaxers Flashcards
What is cyclobenzaprine for?
Muscle spasm generic oral drug, related to amitriptyline, ineffective for pain 2ndary to cerebral or spinal cord dz; also used off label in FM
Cyclobenzaprine MOA?
Central action, maybe at brainstem?
Cyclobenzaprine met/elim?
Enterohepatic recirculation and CYP3A4, 1A2, and 2D6; caution in liver failure
Cyclobenzaprine ADE’s?
Anticholinergic = opposite of SLUDGEBBB that are additive with other anti-cholindergics (GI=paralytic ileum). CNS depression/drowsiness. QT prolongation
Tizanidine use?
Oral for MS, Spasticity, and spinal cord trauma
Tizanidine MOA?
Agonist of presynaptic a2 receptors = decrease activation of polysynaptic motor neurons and reduction in motor tone (not strength!); similar to clonidine but clonidine is mostly relaxation of vasc smooth muscle and Tizanidine only had 10% vascular potency compared to clonidine
Tizanidine met/elim?
Extensive FP; short half life; renal elim of long lasting metabolites; titrate to effect with renal deficiency
Tizanidine ADEs?
Hepatits, rebound hypertonicity in muscle or rebound tachycardia/HTN, additive CNS depression, additive hypotension, asthenia, and xerostomia
Tizanidine monitoring?
LFTs