For more information, please, visit: This is an audio version of a Wikipedia article created for the benefit of those who have vision problems or problem reading at night. This Wikipedia article audio was created under Creative Commons Attribution-ShareAlike. To view the original article, go to
Muscle relaxant wikipedia article audio a muscle relaxant is a drug that affects skeletal muscle function and decreases the muscle tone it may be used to alleviate symptoms such as muscle spasms pain and hyperreflexia the term muscle relaxant is used to refer to two major therapeutic groups neuromuscular blockers and spasmolytic s’ neuromuscular blockers act by
Interfering with transmission at the neuromuscular endplate and have no central nervous system activity they are often used during surgical procedures and in intensive care in emergency medicine to cause temporary paralysis spasmolytic s– also known as centrally acting muscle relaxants are used to alleviate musculoskeletal pain and spasms and to reduce spasticity
In a variety of neurological conditions while both neuromuscular blockers and spasmolytic sar often grouped together as muscle relaxants the term is commonly used to refer to spasmolytic sohn lee history neuromuscular blockers politics analogy clinical use mechanism side effects the earliest known use of muscle relaxant drugs was by natives of the amazon
Basin in south america who used poison tipped arrows that produced death by skeletal muscle paralysis this was first documented in the 16th century when european explorers encountered it this poison known today as kirari led to some of the earliest scientific studies in pharmacology it’s active ingredient to occurring as well as many synthetic derivatives played a
Significant role in scientific experiments to determine the function of acetylcholine in neuromuscular transmission by 1943 neuromuscular blocking drugs became established as muscle relaxants in the practice of anesthesia and surgery the us food and drug administration approved the use of carry cipro doll in 1959 mattacks alone in august 1962 and cyclobenzaprine
In august 1977 other skeletal muscle relaxants of that type used around the world come from a number of drug categories and other drugs used primarily for this indication include orphan adrene clorox s own tizzy nadine diazepam tetras fm and other benzodiazepines meh phoenix alone metha car bomb all dantrolene baclofen drugs once but no longer or very rarely used
To relax skeletal muscles include ma probem 8 barbiturates methaqualone glutamate and the like some subcategories of opioids have muscle relaxant properties and some are marketed in combination drugs with skeletal and /or smooth muscle relaxants such as whole opium products some key toba medan pyramide and fentanyl preparations and equities ik muscle relaxation
And paralysis can theoretically occur by interrupting function at several sites including the central nervous system myelinated somatic nerves unmyelinated motor nerve terminals nicotinic acetylcholine receptors the motor endplate and the muscle membrane or contractile apparatus most neuromuscular blockers function by blocking transmission at the end plate of
The neuromuscular junction normally a nerve impulse arrives at the motor nerve terminal initiating an influx of calcium ions which causes the exocytosis of synaptic vesicles containing acetylcholine acetylcholine then diffuses across the synaptic cleft it may be hydrolyzed by acetylcholine esterase or bind to the nicotinic receptors located on the motor endplate
The binding of two acetylcholine molecules results in a conformational change in the receptor that opens the sodium potassium channel of the nicotinic receptor this allows na+ and see a plus ions to enter the cell and k plus ions to leave the cell causing a depolarization of the endplate resulting in muscle contraction following depolarization the acetylcholine
Molecules are then removed from the endplate region and enzymatically hydrolyzed by acetylcholinesterase normal and plate function can be blocked by two mechanisms nondepolarizing agents such as tuba kareem block the agonist acetylcholine from binding to nicotinic receptors and activating them thereby preventing depolarization alternatively depolarizing agents
Such as succinylcholine are nicotinic receptor agonists which mimic ach block muscle contraction by depolarizing to such an extent that it desensitizes the receptor and it can no longer initiate an action potential and cause muscle contraction both of these classes of neuromuscular blocking drugs are structurally similar to acetylcholine the endogenous ligand in
Many cases containing two acetylcholine molecules linked end-to-end by a rigid carbon ring system as in pancuronium the generation of the neuronal signals in motor neurons that cause muscle contractions are dependent on the balance of synaptic excitation and inhibition the motor neuron receives spasmolytic agents generally work by either enhancing the level of
Inhibition or reducing the level of excitation inhibition is enhanced by mimicking or enhancing the actions of endogenous inhibitory substances such as gaba because they may act at the level of the cortex brainstem or spinal cord or all three areas they have traditionally been referred to as centrally acting muscle relaxants however it is now known not every agent
In this class has cns activity so this name is inaccurate most sources still use the term centrally acting muscle relaxant according to mesh dantrolene is usually classified as a centrally acting muscle relaxant the world health organization in its atc uses the term centrally acting agents but adds a distinct category of directly acting agents for dantrolene use of
This terminology dates back to at least 1973 the term spasmolytic is also considered a synonym for antispasmodic spasmolytic such as carry cipro doll cyclobenzaprine mattacks alone and metha car bomb all are commonly prescribed for low back pain or neck pain fibromyalgia tension headaches and myofascial pain syndrome however they are not recommended as first-line
Agents in acute low back pain they are not more effective than paracetamol or non-steroidal anti-inflammatory drugs and in fibromyalgia they are not more effective than antidepressants nevertheless some evidence suggests muscle relaxants can add benefit to treatment with nsaids in general no high quality evidence supports their use no drug has been shown to
Be better than another and all of them have adverse effects particularly dizziness and drowsiness concerns about possible abuse and interaction with other drugs especially if increased sedation is a risk further limit their use a muscle relaxant is chosen based on its adverse effect profile tolerability and cost muscle relaxants were not advised for orthopedic
Conditions but rather for neurological conditions such as spasticity in cerebral palsy and multiple sclerosis dantrolene although thought of primarily as a peripherally acting agent is associated with cns effects whereas baclofen activity is strictly associated with the cns muscle relaxants are thought to be useful in painful disorders based on the theory that
Pain induces spasm and spasm causes pain however considerable evidence contradicts this theory in general muscle relaxants are not approved by fda for long-term use however rheumatologists often prescribe cyclobenzaprine nightly on a daily basis to increase stage for sleep by increasing this sleep stage patients feel more refreshed in the morning improving sleep is
Also beneficial for patients who have fibromyalgia muscle relaxants such as tisane adine are prescribed in the treatment of tension headaches as a pam and carisoprodol are not recommended for older adults pregnant women or people who suffer depression or for those with a history of drug or alcohol addiction because of the enhancement of inhibition in the cns most
Spasmolytic agents have the side effects of sedation drowsiness and may cause dependence with long-term use several of these agents also have abuse potential and their prescription is strictly controlled the benzodiazepines such as diazepam interact with the gaba a receptor in the central nervous system while it can be used in patients with muscle spasm of almost
Any origin it produces sedation in most individuals at the doses required to reduce muscle tone baclofen is considered to be at least as effective as diazepam in reducing spasticity and causes much less sedation it acts as a gaba agonist at gaba b receptors in the brain and spinal cord resulting in hyper polarization of neurons expressing this receptor most likely
Due to increased potassium ion conductance baclofen also inhibits neural function presynaptic ly by reducing calcium ion influx and thereby reducing the release of excitatory neurotransmitters in both the brain and spinal cord it may also reduce pain in patients by inhibiting the release of substance p in the spinal cord as well clonidine and other imidazole een
Compounds have also been shown to reduce muscle spasms by their central nervous system activity today nadine is perhaps the most thoroughly studied clonidine analog and is an agonist at alpha-2 adrenergic receptors but reduces spasticity at doses that result in significantly less hypotension than clonidine neurophysiologic studies show that it depresses excitatory
Feedback from muscles that would normally increase muscle tone therefore minimizing spasticity furthermore several clinical trials indicate that designer dean has a similar efficacy to other spasmolytic agents such as diazepam and baclofen with the different spectrum of adverse effects the high donto and derivative dantrolene is a spasmolytic agent with a unique
Mechanism of action outside of the cns it reduces skeletal muscle strength by inhibiting the excitation contraction coupling in the muscle fiber in normal muscle contraction calcium is released from the sarcoplasmic reticulum through the ria knotting receptor channel which causes the tension generating interaction of actin and myosin dantrolene interferes with the
Release of calcium by binding to the ria knotting receptor and blocking the endogenous ligand ria knotting by competitive inhibition muscle that contracts more rapidly is more sensitive to dantrolene than muscle that contracts slowly although cardiac muscle and smooth muscle are depressed only slightly most likely because the release of calcium by their sarcoplasmic
Reticulum involves a slightly different process major adverse effects of dantrolene include general muscle weakness sedation and occasionally hepatitis other common spasmolytic agents include meth acaba mall carisoprodol clorox asone cyclobenzaprine gabapentin mattacks alone and orphan adrene muscle relaxants are very powerful drugs which may produce negative effects
Including heart failure and paralysis patients most commonly report sedation as the main adverse effect of muscle relaxants usually people become less alert when they are under the effects of muscle relaxant drugs people are normally advised not to drive vehicles or operate heavy machinery while under muscle relaxants effects cyclobenzaprine produces confusion and
Lethargy as well as anticholinergic side effects when taken in excess or in combination with other substances it may also be toxic while the body adjusts to this medication it is possible for patients to experience dry mouth fatigue lightheadedness constipation or blurred vision some serious but unlikely side-effects may be experienced including mental or mood changes
Possible confusion and hallucinations and difficulty urinating in a very few cases very serious but rare side effects may be experienced irregular heartbeat yellowing of eyes or skin fainting abdominal pain including stomachache nausea or vomiting lack of appetite seizures dark urine or loss of coordination patience taking care isa pro doll for a prolonged time have
Reported dependence withdrawal and abuse although most of these cases were reported by patients who had had a history of addiction these effects were also reported by patients who took it in combination with other drugs with abuse potential and in fewer cases there were reports of carry cipro doll associated abuse when used without other drugs with abuse potential
Common side effects eventually caused by mattacks alone include dizziness headache drowsiness nausea irritability nervousness upset stomach and vomiting severe side effects may be experienced when consuming mattacks alone such as severe allergic reactions chills fever and sore throat may require medical attention other severe side effects include unusual or severe
Tiredness or weakness as well as yellowing of the skin or the ice when baclofen is administered intrical lee it may cause cns depression accompanied with cardiovascular collapse and respiratory failure susannah dean may lower blood pressure this effect can be controlled by administering a low dose at the beginning and increasing it gradually
Transcribed from video
Muscle relaxant – Wikipedia Article Audio By Wikipedia Audio
