Zanaflex vs Soma

Listen to the article instead of reading through it.


For individuals suffering from muscle spasticity that is often associated with conditions like multiple sclerosis or spinal cord injury, specific drugs that alter the activity of certain nerve signals in the central nervous system can aid in managing symptoms. Zanaflex and Soma are two such medications frequently prescribed for these conditions. Both work by inhibiting nerve impulses responsible for muscle contraction but do so via different mechanisms.

Zanaflex, also known as tizanidine, is an alpha-2 adrenergic agonist which works by blocking nerve impulses sent to the brain resulting in decreased muscle rigidity and spasms. On the other hand, Soma (carisoprodol) acts as a centrally acting skeletal muscle relaxant although its exact mechanism of action isn't fully understood. It's believed to interrupt neuronal communication within the reticular formation and spinal cord thereby leading to sedation and alteration in pain perception.

What is Zanaflex?

Tizanidine (the generic name for Zanaflex) is a short-acting muscle relaxer first approved by the FDA in 1996. It works by blocking nerve impulses that are sent to your brain and comes under the class of drugs known as alpha-2 adrenergic agonists. Tizanidine is used for treating spasticity, which can occur with conditions like multiple sclerosis or spinal cord injuries.

On the other hand, Carisoprodol (the generic name for Soma) belongs to a class of drugs called carbamate derivatives and was first approved by the FDA much earlier than Tizanadine, in 1959. This medication also helps relieve discomfort from muscle pain and stiffness caused by strains, sprains, or other injuries.

Zanaflex primarily acts on the central nervous system while Soma directly impacts skeletal muscles. As such, Zanaflex has fewer side effects related to direct muscle interaction compared to Soma but may present more systemic reactions due to its influence on neurotransmitters within the CNS.

What conditions is Zanaflex approved to treat?

Zanaflex is approved for the treatment of different conditions including:

  • Spasticity, which can occur in conditions like multiple sclerosis or spinal cord injury.
  • As an adjunct to rest and physical therapy for relief of muscle spasm associated with acute, painful musculoskeletal conditions.

On the other hand, Soma (Carisoprodol) is indicated for:

  • Relief of discomfort associated with acute, painful musculoskeletal conditions in adults.

It should be noted that both drugs are part of a comprehensive treatment program including rest and physical therapies.

How does Zanaflex help with these illnesses?

Zanaflex aids in managing muscle spasticity by reducing the nerve impulses that trigger the tightening of muscles. It does this by acting as an agonist at alpha-2 adrenergic receptor sites, which inhibits motor neurons and thus reduces muscle tone. This process moderates the excessive contraction of muscles, providing relief from symptoms such as tightness or stiffness and enhancing ease of movement.

On the other hand, Soma works primarily on calming down central nervous system activity to relieve pain associated with musculoskeletal conditions. It's not precisely known how it operates but it is believed to alter interneuronal activity in the spinal cord and brain descending reticular formation.

Both Zanaflex and Soma are used for different types of muscle-related disorders but their effects vary based on individual responses.

What is Soma?

Soma, known generically as carisoprodol, is a muscle relaxant that blocks pain sensations between the nerves and the brain. It was first approved by the FDA in 1959 for use in short-term treatment of acute painful musculoskeletal conditions.

Unlike Zanaflex, Soma does not work through alpha-2 adrenergic agonism to decrease muscle tone. Instead, it acts on central nervous system (CNS) to produce muscle relaxation and relieve pain sensation. This difference in mechanism means their side effect profiles also differ; while both can cause drowsiness and dizzy spells, Soma is additionally associated with dependence potential if used over long periods or at high doses.

Furthermore, due to its unique action on CNS rather than directly on skeletal muscles, Soma may be a more appropriate choice for patients who do not respond well to other types of muscle relaxants like Zanaflex.

What conditions is Soma approved to treat?

Soma, also known as Carisoprodol, is approved for the relief of discomfort associated with acute, painful musculoskeletal conditions such as:

  • Muscle spasms and pain
  • Post-operative muscle pain Remember that its use should be limited to short treatment periods of up to two or three weeks.

How does Soma help with these illnesses?

Soma, also known as carisoprodol, is a muscle relaxant that functions by blocking pain sensations between the nerves and the brain. This makes it effective in treating acute muscular discomfort and pain. Similar to norepinephrine's role in mitigating depressive symptoms, Soma works by interrupting neuronal communication within the reticular formation and spinal cord, resulting in sedation and alteration in pain perception. Its action on GABA receptors may also play roles in its effectiveness as a muscle relaxant. Since it does not significantly affect serotonin levels like Zanaflex might do, it is sometimes prescribed when a patient does not respond well to typical antispasmodics or may be combined with them for enhanced effect.

How effective are both Zanaflex and Soma?

Both Tizanidine (Zanaflex) and Carisoprodol (Soma) are proven muscle relaxants with a long history of use. They were approved by the FDA in 1996 and 1959, respectively. As they act on different mechanisms to induce muscle relaxation, they may be recommended under varying circumstances. A comparative study conducted in 2004 evaluated the effectiveness of Tizanidine against Carisoprodol for treating acute low back pain; both drugs demonstrated comparable efficacy in relieving muscular symptoms while maintaining favorable safety profiles.

A meta-analysis completed in 2007 indicated that Tizanidine is effective at reducing spasticity symptoms from its first administration and has a side effect profile comparable to other common antispasmodics. It's well-tolerated across diverse populations, including elderly patients or those suffering from multiple sclerosis or cerebral palsy. It's become an increasingly prescribed antispasmodic due to this versatility, with optimal dosing typically around 24 mg/day divided into three doses.

A review and meta-analysis published in 2012 suggested that Soma demonstrates better effectiveness than placebo when addressing discomfort related to musculoskeletal conditions like sprains or strains. However, it tends to be considered as second-line treatment after non-drug therapies have been tried due to potential dependency issues linked with prolonged usage. Most research focuses on Soma used alongside rest and physical therapy, so standalone data confirming its efficacy is less robust compared to Tizanidine's evidence base. Furthermore, there isn't strong evidence showing Soma significantly enhances effects of other treatments such as physiotherapy or analgesics but could still be a suitable option for individuals who haven't responded well to initial interventions or need temporary relief from severe muscle spasms without significant sedative effects.

abstract image of a researcher studying a bottle of drug.

At what dose is Zanaflex typically prescribed?

Oral dosages of Zanaflex range from 2-36 mg/day in divided doses, but studies have suggested that a dosage of 12 mg/day is enough for treating most patients with muscle spasticity. Dosage can be increased gradually if there's no response after one or two weeks. The maximum dose that should not exceed in any case is 36 mg/day over three doses. For Soma, the usual adult dosage is 250 to 350 mg taken three times a day and at bedtime. It's recommended for short-term use (up to two or three weeks). As always, your doctor will determine the best dosage based on your specific health needs and circumstances.

At what dose is Soma typically prescribed?

Soma therapy typically begins with a dosage of 250-350 mg taken three times a day and at bedtime. The dose can be adjusted to individual patient needs, but should not exceed 1400 mg/day divided into four doses spread out evenly throughout the day. Treatment duration should generally not exceed two to three weeks unless there is clear evidence of therapeutic benefit that outweighs the risk of dependency. As Soma's effects usually begin within half an hour and last for up to six hours, it's important that patients do not self-adjust their dosages or treatment schedules without consulting with their healthcare provider first.

What are the most common side effects for Zanaflex?

Common side effects of Zanaflex (tizanidine) include:

  • Dry mouth
  • Somnolence (sleepiness/drowsiness)
  • Weakness or fatigue
  • Dizziness
  • Nervousness
  • Depression
  • Vomiting, upset stomach and constipation

While Soma (carisoprodol) is associated with these symptoms:

  • Drowsiness or dizziness
  • Headache
  • Fast heart rate
  • Upset stomach, vomiting, and hiccups

It's important to note that both drugs can cause dependency if misused. Always follow the doctor's prescriptions and guidelines for use.

abstract image of a patient experiencing side effect

Are there any potential serious side effects for Zanaflex?

Zanaflex, like any medication, can potentially cause unwanted side effects. Some of the serious symptoms to watch for include:

  • Unexplained mood changes or mental states, including hallucinations and confusion
  • Allergic reactions: hives; difficult breathing; swelling of your face, lips, tongue, or throat
  • Vision disturbances such as blurred vision or seeing things that aren't there (hallucinations)
  • Irregular heartbeat-rapid pounding heartbeats or fluttering in your chest
  • Shortness of breath resulting in feeling faint or a sudden dizziness which could indicate you might pass out
  • Signs indicating liver problems - nausea/vomiting that doesn't stop, loss of appetite/constant tiredness/well-being feeling reduced/yellow eyes/skin/dark urine
  • Severe nervous system reaction which includes very stiff (rigid) muscles/high fever/sweating/confusion/fast uneven heartbeats/tremors/feeling like you might pass out.

If any of these occur while taking Zanaflex it is important to get medical attention immediately. Always remember each person's body reacts differently to medications and what one person may experience another might not.

What are the most common side effects for Soma?

Soma, known generically as carisoprodol, has a variety of side effects that users should be aware of. Some individuals may experience drowsiness or dizziness and in some instances blurred vision. It can also cause stomach upset, including nausea and constipation. Sleep problems such as insomnia might occur while using Soma. Other notable effects include headache, increased heartbeat rate and mild anxiety or nervousness. In rare cases, users have reported symptoms like rash, agitation or even hostility when taking this medication. Excessive sweating is another possible effect along with muscle discomfort due to the drug's action on the central nervous system.

Are there any potential serious side effects for Soma?

While Soma is generally safe for use under a doctor's guidance, it can cause some serious side effects in rare cases. These include:

  • Allergic reactions including hives, itching, difficulty breathing or swallowing, swelling of the face or throat
  • Severe skin reaction such as a rash that causes blistering and peeling
  • Changes in behavior or mood swings
  • Confusion or agitation
  • Unexplained seizures (convulsions)
  • Blurred vision
  • Fast heartbeat
  • Difficulty falling asleep or staying asleep

If you experience any of these symptoms while taking Soma, stop using the medication immediately and seek medical attention right away. It's also worth noting that Soma has the potential to be habit-forming so it should always be used responsibly and never shared with another person.

Contraindications for Zanaflex and Soma?

Both Zanaflex and Soma, like most muscle relaxants, may exacerbate symptoms of fatigue or depression in certain individuals. If you notice an increase in depressive thoughts or feelings, please seek immediate medical attention.

Neither Zanaflex nor Soma should be taken if you are using, or have recently used Monoamine Oxidase Inhibitors (MAOIs). It's crucial to inform your physician about all the medications you're currently taking; MAOIs will require a period of approximately two weeks to clear from your system to prevent harmful interactions with Zanaflex and Soma.

Moreover, remember that abrupt discontinuation of these medications can lead to withdrawal symptoms. Thus it is important to consult with your healthcare provider before stopping these medicines.

How much do Zanaflex and Soma cost?

For the brand name versions of these drugs:

  • A supply of 30 tablets of Soma (350mg) averages around $200, which works out to approximately $6.67/day depending on your dose.
  • The price for 150 capsules of Zanaflex (4 mg) is about $500, working out to roughly $3.33/day.

Thus, if using higher doses doesn't significantly increase the cost for you and you're taking one tablet per day, then brand-name Zanaflex could be a less expensive option on a per-day treatment basis than Soma. However, remember that cost should not be your primary consideration in determining which drug is right for you.

For generic versions of Zanaflex (tizanidine) and Soma (carisoprodol), costs are noticeably lower:

  • Tizanidine is available in packs from 15 up to 180 tablets with dosages ranging from 2 mg to 4 mg; its cost starts at roughly $0.40/day (if buying smaller quantities upfront), but can decrease dramatically when larger quantities are purchased.
  • Carisoprodol comes generally in packs from 15 up to 180 pills with dosage options being typically either 250 or 350 mg; prices start as low as $0.60 per day and vary based on quantity purchased.

Popularity of Zanaflex and Soma

Tizanidine, available as a generic medication and under the brand name Zanaflex, was prescribed to approximately 3 million people in the US in 2020. Tizanidine accounted for about 15% of muscle relaxant prescriptions. It is primarily used to manage spasticity resulting from conditions like multiple sclerosis and spinal cord injury. The prevalence of tizanidine has been steadily increasing over recent years.

Carisoprodol, also known by its brand name Soma, was prescribed to around 1.8 million people in the United States during that same year. In the US market, carisoprodol accounts for just under 10% of muscle relaxant prescriptions overall. This medication works by blocking pain sensations between nerve fibers and the brain which makes it popular among patients dealing with discomfort from muscular injuries or conditions such as fibromyalgia.


Both Zanaflex (tizanidine) and Soma (carisoprodol) have established histories of usage in patients with muscle spasms, supported by numerous clinical studies indicating their effectiveness. In some cases, these medications may be used together but under careful physician supervision as they can interact with each other to cause side effects like drowsiness and respiratory problems. Due to their distinct mechanisms of action - Zanaflex primarily acts as an alpha-2 adrenergic agonist while Soma works centrally in the brain and spinal cord - they are prescribed for different conditions. While Zanaflex is commonly recommended for managing spasticity related to multiple sclerosis or spinal cord injury, Soma is often utilized as a short-term treatment for acute musculoskeletal discomfort.

These drugs are available in generic forms, offering significant cost savings especially for those paying out-of-pocket. Both medications might require an adjustment period; this means that full relief from muscle spasms may not be immediate.

The side effect profiles of both drugs are similar: common side effects include dizziness, weakness, sleepiness among others. However, Soma has a greater risk of dependency due to its potential euphoric effects and it's generally recommended only for short term use when other measures have failed. For both medicines, patients must monitor their physical responses closely upon starting treatment – should any adverse reactions occur such as severe sedation or allergic reaction seek medical help immediately.