Muscle relaxants centrally acting agents

CENTRALLY ACTING MUSCLE RELAXANTS AND ANTIPARKINSONISM AGENTS 15... 

Priadel lithium carbonate lithium citrate, pridinol [inn] (pridinol mesilate [jan]) is a diphenylpiperidine derivative with anticholinergic activity. It can be used as a centrally acting skeletal muscle relaxant and ANTIPARKINSONIAN AGENT. 

Directly acting muscle relaxants, such as dantrolene. Centrally acting agents are not effective because they ultimately act at the level of the spinal cord. 

Kava pyrones are potent, centrally acting skeletal muscle relaxants. They act as hypnotics, antipyretics, sedatives, local anaesthetics, smooth muscle relaxants and antifungal agents. No interaction with benzodiazepine drugs or with moderate consumption of alcohol occurs, nor does kava impair mental alermess. However, continually chewing the root can destroy tooth enamel and eventually becomes habit forming (Bone 1994). 

Cydobenzaprine (Flexeril) [Skeletal Muscle Relaxant/ANS Agent] Uses Relief of muscle spasm Action Centrally acting skeletal muscle relaxant reduces tonic somatic motor activity Dose 5-10 mg PO bid-qid (2-3 wk max) Caution [B, ] Shares the toxic potential of the TCAs urinary hesitancy, NAG Contra Do not use concomitantly or w/in 14 d of MAOIs hyperthyroidism heart failure arrhythmias Disp Tabs SE Sedation anticholinergic effects Interactions T Effects of CNS depression W/ CNS depressants, TCAs, barbiturates, EtOH T risk of HTN convulsions W/ MAOIs EMS Use caution w/ other CNS depressants concurrent EtOH use can T CNS depression OD May cause N/V,... 

Skeletal muscle relaxants fall into three major categories those that reduce spasticity, those that cause neuromuscular blockade and those that work at the cellular level. Spasmolytic agents (e.g. metho-carbamol, guaifenesin) act centrally whereas neuromuscular blockers (e.g. succinylcholine (suxamethonium), pancuronium, atracurium) act at the neuromuscular end plate to produce muscular relaxation. Dantrolene falls into the third category and acts within the muscle cell itself to produce relaxation. 

Mepnibamate is also a centrally acting skeletal muscle relaxant. The agents in this group find use in a number of conditions, such as strains and. sprains that may produce acute muscle. spasm. Tliey have intemeuronal blocking properties at the level of the spinal cord, which are. said to be partly respon.sihle for. skeletal muscle relaxation. Also, thc gencral CNS depressant properties they pos.se.ss may contribute to. or be mainly responsible for. the skeletal muscle relaxant activity. Dihydric compounds and their carbamate (urethane) derivatives, as described above in the di.scussion of meprobamate, arc prominent members of the gn>up. 

These agents act at the level of the brain stem to initiate muscle relaxation. This may be related to a blockade of afferent pathways, or by a central depression of central nervous system (CNS) function. 

Central Muscle Relaxants - There continues to be considerable controversy as to whether this group of medicinal agents is effective clinically by the oral route. Their effectiveness in animal experiinents and when administered parenterally to humans is well established. The need for a centrally acting skeletal muscle relaxant which is orally effective at a reasonable dose continues to exist. 

Mecfianism of Action An anticholinergic agent that blocks central cholinergic receptors (aids in balancing cholinergic and dopaminergic act ivity) Tiicrapc tic Effect Decreases salivation, relaxes smooth muscle. 

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