Pain is a distressing feeling that can impact your day-to-day activities and quality of life. The concept of pain is a vast topic, as there are numerous ways of describing the sensation based on intensity, severity, and causative factors. It is crucial to identify it on time and get the help required through medications, therapy, or a combination of both.
Muscle relaxants are the treatment options for muscle pain or myalgia involving ligaments, tendons, and soft tissues brought about by injuries, trauma, overuse, or illness. They improve gait and facilitate day-to-day activities through reduced pain intensity.
With the growing incidence of lower back pain, the popularity of muscle relaxants has accelerated in the last few decades between 2005 and 2016; the US recording more than 30 million prescriptions of muscle relaxants for ambulatory care visits in 2016. Carisoprodol is one such muscle relaxant that has been FDA-approved for acute musculoskeletal condition-related pain relief. The medicine was developed in Wallace Laboratories as a substitute for Meprobamate with the aim of providing better muscle-relaxing properties, less potential for addiction, and a lower risk of overdose.
The popularity of the medication grew over the years, with the market expected to grow by 9.1% annually. (CAGR 2023 – 2030). While rising incidences of muscle pain and spasms have played a crucial role, the non-opioid nature of the medication has generated public favor in increasing the demand for it.
What makes Carisoprodol unique
Carisoprodol is a centrally-acting skeletal muscle relaxant working on the central nervous system (CNS) to produce satisfactory analgesic properties.
Recent studies have shown that Carisoprodol can directly gate and allosterically modulate the type A GABA receptors with nominal direct gating effects in α3β2γ2 receptors and increased volume of amino acids. The orientation of alkyl or hydroxyl groups further influences direct gating effects and imparts anxiolytic effects with muscle-relaxing properties. Its primary metabolite, Meprobamate, is believed to work at the GABA receptors similar to benzodiazepines and is thought to be responsible for Carisoprodol’s therapeutic effects and intensity of pain relief.
A comparative study into the metabolic effects of Tramadol, an equally potent muscle-relaxant, Tramadol, and its active metabolites do not impact the GABA receptors at lower concentrations or have any effect on the glycine receptors that work alongside GABA and help in making you sleep.
The combined ineffectiveness of Tramadol on the glycine receptors with its inhibition of GABA at large concentrations further diminishes its antinociceptive properties. Rather it comes with a risk of convulsions when used immoderately.
Carisoprodol can be helpful in the treatment of fibromyalgia and ease the discomfort of the patient by allowing them to sleep. But for severe conditions, Tramadol is regarded as the first treatment option because of its potent analgesic properties. Tramadol works later than Carisoprodol but lasts longer when used in extended strengths, which makes it favorable for the chronic and severe conditions of muscle spastics.
In a comparative evaluation of two separate studies conducted on fibromyalgia patients, Carisoprodol, when used with Paracetamol and Caffeine in an 8-week parallel study, resulted in effective pain relief, improvement in sleep quality, and a general improvement of sickness-feeling after eight weeks. Drowsiness was observed as a side effect in the study.
In a comparative analysis of Tramadol combined with paracetamol in 315 patients for 15 weeks, There was very low-quality evidence that patient-reported pain relief of 30% or greater and patient-reported pain relief of 50% or greater was better in the combination group as compared to the placebo. There was very low-quality evidence that the combination of Tramadol and paracetamol (acetaminophen) is moderately effective in reducing pain and pain-related symptoms of fibromyalgia.
Carisoprodol vs Baclofen
Baclofen is a lipophilic analog of c-aminobutyric acid (GABA) and Carisoprodol (Soma), used clinically in the management of spasticity and the chronic complications that arise because of it, such as multiple sclerosis and other types of spinal cord lesions.
While comparison studies or mass-spectrum chromatography results have not shown any significant differences, Baclofen has received a customer rating of 6.9 out of 10 from 426 ratings ( 61% positive effect ). In comparison, Carisoprodol has received a customer rating of 9.0 out of 10 from a total of 297 ratings.
A comparative Study of Carisoprodol and Metaxalone
Metaxalone, available under the brand name Skelaxin, is a muscle relaxant used to relieve pain caused by strains, sprains, and other musculoskeletal conditions. While it suppresses brain activity resulting in sedation and reduced pain sensation, it does not directly affect muscle, the motor end plate, or the nerve fiber and does not relax tense skeletal muscles. Additionally, it has been associated with liver damage.
In animal studies, Carisoprodol mechanisms are associated with interneuronal activity in the spinal cord and the brain’s reticular formation to bring out its pain relief and anxiolytic properties. Carisoprodol indirectly impacts the motor end plates but in a safe manner with a low potential for hepatotoxicity, which makes it an effective and safe option.
Effectiveness of Carisoprodol over Cyclobenzaprine
Cyclobenzaprine is a skeletal muscle relaxant structurally related to tricyclic antidepressants that relieve skeletal muscle spasms without interfering with muscle function. While it works well in pain and discomfort caused by strains, sprains, or localized muscle injuries, it is not designed for brain or spinal cord injuries. A few researchers have found the medication effective for lower back pain compared to the placebo in the study. Still, it takes longer to feel the analgesic effects, with a greater incidence of associated side effects.
Carisoprodol works on treating severe muscle spasms due to strains, sprains, or muscle injuries and has been clinically proven to be superior to Cyclobenzaprine and other potent medications like Diazepam in patients with moderately severe back pain without patient discontinuation because of sedation, adverse events, or clinically significant effects on laboratory values or vital signs.
The overall use of Carisoprodol has been proven to deliver successful outcomes from pain conditions without any significant side effects or the risk of liver damage from using it.
The Catch in use of Carisoprodol
Unfortunately, the therapeutic properties of Carisoprodol have led to increased abuse, resulting in it being declared a controlled medicine. According to the results of a 2012 National Survey data, 3.69 million people used Carisoprodol for non-medical reasons, including diversion and trafficking, with the safety revision in Europe recommending a suspension of Carisoprodol throughout the continent in 2007. A similar process in the US in 2011 resulted in the placement of Carisoprodol in the Schedule IV of the Controlled Substances Act and a moderate reduction in its dispensing, especially among younger age groups and injury-based patients.
Despite the controlled nature of Carisoprodol, its popularity remains ever-growing, with its consumption graph forever on the increase. But considering the growing number of addiction cases with its use, further studies are required to form concrete evidence about its liabilities. Public awareness of the abuse potential of Carisoprodol after long-term treatments should be encouraged to enable a mass-education about its risks and benefits.