Skeletal muscle relaxants centrally acting

Methocarbamol (Robaxin) [Skeletal Muscle Relaxant/ Centrally Acting] Uses Relief of discomfort associated w/ painful musculoskeletal conditions Action Centrally acting skeletal muscle relaxant Dose Adults. 1.5 g PO qid for 2-3 d, then 1-g PO qid maint therapy IV form rarely indicated Peds. 15 mg/kg/dose IV, may repeat PRN (OK for tetanus only), max 1.8 g/mVd for 3 d Caution Sz disorders [C, +] Contra MyG, renal impair Disp Tabs, inj SE Can discolor urine drowsiness, GI upset Interactions T Effects Wf CNS depressant, EtOH EMS May cause blurred vision and orthostatic hypotension use caution w/ CNS depressants concurrent EtOH use can T CNS depression OD May cause drowsiness, light-headedness, syncope, and slow shallow breathing symptomatic and supportive... 

Drug Class skeletal muscle relaxant, centrally acting... 

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 A nt] 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 theTCAs 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 d ression W/ CNS dqjressants, TCAs, barbiturates, EtOH t risk of HTN convulsions W/MAOIs EMS Use caution w/ other CNS depressants concurrent EtOH use can t CNS d ession OD May cause N/V,... 

Some Centrally Acting Skeletal Muscle Relaxants... 

Mechanism of Action A centrally-acting skeletal muscle relaxant whose exact mechanism is unknown. Effects may be due to its CNS depressant actions. Therapeutic Effect Relieves muscle spasms and pain. 

Geriatric Considerations - Summary Chlorzoxazone is a centrally acting skeletal muscle relaxant that at higher doses can cause CNS depression. It appears to have modest clinical benefits and is most often used for acute muscle discomfort as compared to chronic muscle pain. It is often taken in combination with acetaminophen. Transient CNS depressant effects place the older adult at risk for falls and related accidents when taking this drug. 

Skeletal muscle relaxants act peripherally at the neuromuscular junction or centrally in the cerebrospinal axis to reduce muscle tone. 

Chlorzoxazone (Paraflex, Parafon Forte DSC, Others) [Skeletal Muscle Relaxant/ANS Drug] Uses Adjunct to rest physical therapy to relieve discomfort associated w/ acute, painful musculoskeletal conditions Action Centrally acting skeletal muscle relaxant Dose Adults. 250-500 mg PO tid-qid Peds. 20 mg/kg/d in 3-4 + doses Caution [C, ] Avoid EtOH CNS depressants Contra Severe liver Dz Disp Tabs SE Drowsiness, tach, dizziness, hepatotox, angioedema Interactions T Effects W/ antihistamines, CNS depressants, MAOIs, TCAs, opiates, EtOH, watercress EMS Use of CNS depressants and concurrent EtOH use can T sedation urine may turn reddish purple or orange OD May cause N/V/D, dizziness, HA, X deep tendon reflexes, hypotension and resp depression symptomatic and supportive, activated charcoal may be effective... 

Katzung PHARMACOLOGY, 9e > Section V. Drugs That Act in the Central Nervous System > Chapter 27, Skeletal Muscle Relaxants > ... 

This is a centrally acting skeletal muscle relaxant whose active metabolite is meprobamate. It is metabolized primarily by CYP2C19,... 

Elenbaas JK. Centrally acting oral skeletal muscle relaxants. Am J Hosp Pharm 1980 37(10) 1313-23. 

Diazepam, the most commonly used benzodiazepine in equine medicine, is used as a component of anesthetic protocols (see Ch. 15) and for the treatment of seizures (see Ch. 9). It induces skeletal muscle relaxation by facilitating the action of the inhibitory neurotransmitter gamma-aminobutyric acid (GABA) within the central nervous system. It acts primarily within the spinal cord and exerts inhibitory effects on polysynaptic reflexes and intemuncial neuron transmission. 

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. 

Dantrolene is a hydantoin class of anticonvulsant that acts outside the central nervous system to produce skeletal muscle relaxation by interfering with excitation contraction coupling. In normally contracting muscle, activation of the ryanodine receptor within the muscle fiber results in calcium release from the sarcoplasmic reticulum and subsequent muscle contraction. Dantrolene interferes with the release of calcium from the sarcoplasmic reticulum by interfering with the ryanodine receptor. The release of calcium in smooth and cardiac muscle is under different control consequently, dantrolene primarily affects skeletal muscle. 

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. 

Chlorzoxazone is used as a centrally acting skeletal muscle relaxant and as an analgesic. It is also a strong oxidizing agent. 

AF 11377 is a 15 residue peptide that acts as a CYTOKINE RECEPTOR ANTAGONIST both in terms of competing for binding with IL-1 at the IL-lRl receptor subtype and also blocks functional responses to IL-1 in human and monkey cells, afloqualone [inn, jan] is a quinazolinone derivative. It is a centrally acting SKELETAL MUSCLE RELAXANT. 

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