Muscle Relaxants and Their Use in Managing Back Pain

Muscle relaxants are a group of drugs that are used to treat muscle spasms, which are sudden involuntary contractions of a muscle. They help relieve pain and can increase the mobility of the affected muscle. They work by the inhibition of signals related to pain in the spinal cord and brain.

There are divided into two groups:

  • Neuromuscular blockers: They work at the site of neuromuscular junctions, where the neuron meets a muscle fiber. They have no effects on the central nervous system
  • Spasmolytics: These act on the central nervous system to help manage pain and spasms. This article refers to spasmolytics when it talks about muscle relaxants.

Some of the common ones are listed below:

  • Benzodiazepines
  • Carisoprodol
  • Chlorzoxazone
  • Cyclobenzaprine

Causes of back pain:

  • Back muscle spasms can occur due to the compression of a nerve caused by a herniated thoracic disk.
  • Excessive strain on the back caused by constant heavy lifting and poor physical health otherwise
  • They can also be caused by arthritis as it increases pressure on the spinal cord resulting in pain. It can also cause spinal stenosis which occurs when the spinal canal narrows.
  • Any injury that causes physical trauma to muscles, tendons and ligaments in the back.
  • Osteoporosis causes vertebrae to become brittle and weak so that they fracture easily. These compression fractures can cause harm to surrounding structures like nerves
  • Abnormal curvature of the spine, as in scoliosis, is a predisposing factor to the development of back pain

Diagnosis of back pain:

Before back pain can be treated, there needs to be confirmed diagnosis for it. Back pain is not a physical pathology that can be visualized. This is why we need to look into the causes for back pain. Back pain caused by any trauma to the vertebrae can be visualized by X-ray imaging. MRIs are useful for visualizing soft tissue structures so that nerve compression and impingement can be seen. Blood tests that detect the levels of Vitamin D and calcium can help diagnose osteoporosis. Since osteoporosis causes a decrease in bone density, it can also be diagnosed with a bone densitometry.

Treatment of Back Pain:

The treatment of back pain involves a more conservative approach. The choice of treatment for back pain is acetaminophen and/or non-steroidal anti-inflammatory drugs (NSAIDS). The use of ice is also popular to supplement the therapy. A period of bed rest is followed by light strengthening exercises is also recommended.

When this approach does not work, muscle relaxants are prescribed to help alleviate the pain. They are more specifically used in the treatment of acute back pain. They are used as a part of a short course, usually three weeks long. They are also used for their sedative effect for use in those patients that have back pain so severe it leads to disturbance in their sleep.

The problems associated with muscle relaxants:

Side Effects:

Like all drugs, they also have their own side effects that occur because they exert their effects on the brain and spinal cord which results in the depression of the central nervous system. This can lead to many serious problems such as:

  • Drowsiness: A general feeling of sleepiness and grogginess
  • Lightheadedness: Feeling dizzy
  • Gait Disturbances: Problems walking and coordinating movements
  • Headache
  • Blurred Vision
  • Fatigue and Nausea

For this reason, they are mostly confined to use in young, healthy individuals because a fall due to side effects can lead to fractures or worse in the elderly population or those that are prone to seizures. The lethargy and dizziness is most commonly associated with cyclobenzaprine.


  • The drugs must also be used after consultation with a personal doctor if the patient has any condition affecting their liver, kidney or heart. This is because tizanidine can lower blood pressure and baclofen can affect the heart and lungs.
  • Any woman that is pregnant, breastfeeding or wanting to become pregnant should also consult with their doctor before using these relaxants.

Any changes that occur in the body or to pre-existing conditions with the use of these drugs should immediately be reported to a doctor for the patient’s own health and safety.

  • The drugs should not be used together with alcohol as the combined effect of both on the nervous system can be very unstable.
  • The drugs should also not be used along with sleeping medications

Those using muscle relaxants should also take due diligence before driving or operating any heavy machinery.


These relaxants have the potential to be abused. This is because the sedative effect that it has on the nervous system mimics the effects of many recreational drugs. This is why it is best to limit the duration of treatment of back pain with these to less than a month. An overdose of muscle relaxant can cause the breathing to slow down to the point where it can be fatal.

Since they have an addicting quality to them, their use must not be stopped abruptly as withdrawal symptoms can develop (most commonly with carisoprodol) and they can cause harm to the body. These withdrawal symptoms include but are not limited to nausea, vomiting and trouble sleeping. In severe cases they can affect behavior and lead to irritability and aggressiveness. They should be tapered off gently, with each dose requiring a lesser and lesser amount until the patient is ready to be let off the medicine.

To properly treat back pain, medicines should be followed along with changes in lifestyle. This includes activities and light exercises that strengthen, support and stabilize the spine. When all else fails, the last resort for the treatment of back pain is surgery.

Our spines are an important part of our axial skeleton. They play an instrumental role in helping us be up right, walking on two legs mammals. This makes it important for us to make sure that we are at all times taking care of our backs. This includes correcting our posture, making sure that our bedding is comfortable and eating nutritious to maintain optimum health.