Over The Counter Muscle Relaxers
What Is The Best OTC Muscle Relaxer?
You can order OTC muscle relaxers in our online pharmacy. You can buy Soma (Carisoprodol), Baclofen, Zanaflex (Tizanidine), Robaxin (Methocarbamol) without a prescription. Our advantage is a fast overnight delivery around the whole country. Buying generic over the counter muscle relaxants online is convenient. You can both save your money on generic drugs and save your money by getting drugs by mail.
Our pharmacology topic today is muscle relaxers. Muscle relaxers decrease muscle tone. They are used to treat symptoms associated with increased muscle tone such as muscle spasms, hyperreflexia, and pain.
Technically the term muscle relaxants can be subdivided into two major groups including neuromuscular blockers and spasmolytics.
Neuromuscular blockers work in the periphery. They block N1 receptors in the neuromuscular junction to stop skeletal muscle contractions. They are useful during certain types of surgery and for procedures such as intubation to cause short-term flaccid paralysis. Most spasmolytic work centrally at the level of the spinal cord or brain.
The term muscle relaxants are most often used to refer just to spasmolytics and these are the topic of this article.
Remember that an indication is a reason the drug is used. As mentioned, muscle relaxants are often indicated for the treatment of painful musculoskeletal conditions.
Some examples include treating muscle spasms associated with overexertion and helping manage the spasticity of severe chronic disorders, like multiple sclerosis and cerebral palsy. These drugs usually work best when used alongside physical therapy.
Muscle Relaxers Mechanism Of Action
To understand the mechanisms for the muscle relaxers like Diazepam, Tizanidine and Baclofen let's review a cross-section of the spinal cord.
Let's have a closer look at the motor neuron synapses.
For voluntary muscle contraction of limbs, the upper motor neuron, or a UMN, is activated in the cerebral cortex. And action potentials travel down the spinal cord or the synapse with lower motor neurons or elements at the level of exit.
Inhibitory interneurons regulate the excitation of the elements. An action potential traveling down the upper motor neuron will cause the release of excitatory neurotransmitters like norepinephrine or glutamate onto the LMN, which will then activate the skeletal muscle.
The inhibitory neurotransmitter GABA is released from the inhibitory neuron. It acts to decrease the excitation of the element by increasing chloride permeability in the element.
Diazepam and Benzodiazepine used for muscle spasms will bind to the BZD binding site of GABA-A receptors located on cell bodies of the lower motor neurons to increase the permeability of chloride even more. Thus, the action of Diazepam augments or increases the action of GABA and hyperpolarizes the cell even more. The hyper-polarization decreases the frequency of action potentials traveling through the element to the muscle.
Baclofen is a drug used for spasms associated with spinal cord injuries. Baclofen activates GABA-B receptors in the postsynaptic membrane to cause an increase in potassium conductance in the alamin, which also causes hyperpolarization.
There are also GABA-B receptors in the presynaptic membrane of the upper motor neuron. Activation of these receptors leads to less release of calcium ions and consequently less release of excitatory neurotransmitters like norepinephrine glutamate from the UMN onto the element.
Consequently, fewer action potentials travel down the LMN to reach the muscle.
Tizanidine is one of the drugs used for spasms associated with multiple sclerosis. This drug is an alpha-2 agonist and binds to UMN and axon terminals and causes less release of excitatory neurotransmitter.
Another muscle relaxer Dantrolene is a direct acting muscle relaxant that blocks ryanodine receptors in skeletal muscles. Therefore, unlike the other muscle relaxants, it doesn't act in the CNS.
Dantrolene is indicated for the treatment of muscle spasms associated with multiple sclerosis, cerebral palsy, spinal cord injuries and malignant hyperthermia or MH.
MH is a severe reaction characterized by fever, muscle rigidity and tachycardia. Although rare, MH occurs in susceptible individuals that are exposed to volatile general anesthetics like Halothane and depolarizing neuromuscular blockers like succinylcholine.
Dantrolene binds to the ryanodine channel and prevents it from opening when the action potential reaches the DHPR. This prevents a release of calcium from the sarcoplasmic reticulum and prevents muscle contraction.
Dantrolene is more selective for skeletal muscle. Because the heart has RyR2 type 2 receptors instead of type 1, that is in skeletal muscle.
Several muscle relaxers are used for local muscle spasms associated with overexertion or injuries. Manual laborers or those in car accidents are examples of individuals who may have these drugs prescribed by a physician.
Common muscle relaxers that fit this category are:
The mechanism is not well understood, but it is believed that they are to act at a brainstem.
Adverse Effects Of Muscle Relaxers
Most relaxers that act in the CNS have the following adverse effects in common:
- lightheadedness or dizziness;
- muscle weakness.
Due to these effects, it is important to advise patients and monitor them while taking these medications.
Also, since most muscle relaxers are CNS depressants, don't mix with alcohol and use caution when driving an operating machinery.
Order OTC muscle relaxers like Soma And Baclofen in our pharmacy without a prescription. No more staying in long lines in hospital! Simply buy generic over the counter muscle relaxers in order to get rid of your pain.