In this article, we examine current therapies for spasticity caused by multiple sclerosis (MS) and compare them with Sativex, a cannabis derivative that is being researched but has not yet been approved by the Food and Drug Administration (FDA). Research shows Sativex is effective in treating spasticity, which is a common symptom of MS.

For people who have conditions like cancer, Parkinson’s disease, seizures, or MS, medical cannabis may provide relief from symptoms. Medical cannabis is another tool for doctors to help patients manage their conditions and symptoms.

Research on the use of cannabis to treat symptoms of MS has been limited, but some studies in the past decade have shown positive results.

According to the National MS Society, spasticity refers to muscle spasms and feelings of stiffness. It is a common symptom in people who have MS.

When MS damages the nerves that control muscles, it can result in spasticity that impairs movement and causes pain and stiffness. Spasticity usually occurs in the legs, and it can draw the legs up toward the body with painful cramping or cause spasms in the lower back.

For some people who have muscle weakness, spasticity can be beneficial to a degree, as it provides them with the stiffness needed to walk. But when the pain becomes too much to bear, it may be time to consider medication.

Dr. Vijayshree Yadav has studied the use of alternative medication in MS for many years.

A 2010 study of hers found, “In a review of six controlled studies evaluating a combination of THC and CBD [tetrahydrocannabinol and cannabidiol, the active ingredients in cannabis] for spasticity in MS, it was found that THC–CBD was well tolerated and improved patient self-reports of spasticity.”

It’s important to note that these improvements were self-reported and there was objectively no difference in symptoms when compared with the placebo group.

In 2014, Yadav authored a set of guidelines for the American Academy of Neurology saying that pill and mouth spray forms of cannabis have shown success in treating spasticity and bladder symptoms in MS patients.

Medications approved to treat MS spasticity include Zanaflex, Baclofen, and Botox. Many other medications are used off-label to treat spasticity, too. The following sections outline how each of them works, how they are taken, and their possible side effects.

Sativex is made by GW Pharmaceuticals and is available by prescription in over 15 countries to treat MS spasticity. In April 2014, the FDA fast-tracked Sativex in the United States. Phase 3 clinical trials for the use of Sativex to treat MS spasticity began in November 2020.

You should speak with your doctor about all the possible risks and benefits before making any treatment decisions. The list below does not include less common side effects, symptoms of possible adverse events, or signs of overdose.

Because many side effects are similar in nature to symptoms of MS, if you experience any change or worsening of MS symptoms, consult your doctor.

For those with MS who prefer to avoid taking pharmaceutical medications, other options are worth looking into. Studies have shown that yoga, water aerobics, and physical therapy can also help reduce the muscle stiffness and pain caused by spasticity.

Sativex was approved for medical use in England in 2019. In trials leading up to this approval, people with MS saw a reduction in spasticity symptoms and no long-term effects on their mood or cognition. Sativex has not yet been approved for use in the United States by the FDA.

Some of the side effects of Sativex include:

  • increased appetite
  • dizziness
  • fatigue
  • memory impairment
  • blurred vision
  • gastrointestinal problems

Sativex facts

How does it work?THC and CBD act as regulators of neural transmitters to reduce limb stiffness and improve motor function.
How do you take it?It’s sprayed on the mucosal lining of the mouth and is meant to be used in addition to other spasticity treatments.
How often do you take it?The dosage varies, but it’s usually adjusted over time with a maximum dose of between 2 and 12 sprays daily.

Baclofen is a muscle relaxer used to treat a variety of MS symptoms.

In very severe cases of muscle spasms, Baclofen can be administered through an implanted pump. Side effects include:

  • confusion
  • dizziness and nausea
  • unusual muscle weakness

Baclofen facts

How does it work?Baclofen acts on the spinal cord nerves to decrease the number and severity of muscle spasms, relieve pain, and improve muscle movement.
How do you take it?It’s taken as a tablet by mouth.
How often?A typical dosage is three times per day.

Botox was originally developed as a nerve gas before World War II. It was first used to treat MS spasticity in 1990 and is now commonly used in cosmetic procedures to fix facial muscles in place.

Side effects include:

  • bruising
  • bleeding
  • pain or weakness in muscles at the injection site
  • neck or back pain

Botox facts

How does it work?Botox causes temporary paralysis of nerves.
How do you take it?It’s given by injection.
How often?A typical dosage is once every 3–4 months.

This medication is commonly used to treat epilepsy. It’s also used as a mood stabilizer for bipolar disorder.

Studies have shown that it can cause serious birth defects if prescribed to pregnant people. It can also cause other side effects like:

  • nausea
  • weakness
  • constipation
  • liver disorders
  • blocking contraception medications from working

Tegretol facts

How does it work?This anticonvulsant drug blocks or reduces nerve transmission from the brain to the rest of the body.
How do you take it?It’s taken as a pill by mouth.
How often?It’s adjusted over time from once a day to several times daily.

Klonopin is more often used to treat muscle tremors in MS than to treat spasticity. It is a benzodiazepine, so it can also be used as a sedative or a hypnotic.

The drug is not safe for those with liver disease or certain respiratory conditions. It can cause:

  • dizziness
  • muscle weakness
  • fatigue
  • confusion
  • lightheadedness
  • depression

Klonopin facts

How does it work?This medication slows the activity of the central nervous system.
How do you take it?It’s taken as a tablet by mouth.
How often?Doses are adjusted over time. Stopping treatment must be gradual because it can cause dependency.

This drug is usually reserved for chronic, severe cases of spasticity where baclofen or gabapentin have not worked.

People with a history of liver damage or severe heart problems should not take this medication, nor should children younger than 5 years old. It may cause dizziness, drowsiness, weakness, and fatigue.

Dantrium facts

How does it work?This muscle relaxant is used to treat spasticity or muscle spasms.
How do you take it?It’s taken as a capsule by mouth.
How often?A typical dosage is adjusted over time from once per day to 3–4 times per day.

Valium has been used to treat spasticity since the 1960s, but it’s no longer the first choice due to the potential for dependence.

In addition to dependence, side effects include:

  • dizziness and drowsiness
  • loss of balance
  • feeling less alert
  • interactions with antihistamines, tranquilizers, alcohol, and other sedatives

Valium facts

How does it work?It slows the transmission of messages from the brain to the nerves.
How do you take it?It’s taken as a pill by mouth.
How often?Doses are adjusted over time. Stopping must be gradual as it can cause dependency.

Gabapentin was originally designed as an antiseizure drug. It’s used more often to treat neuropathic pain in MS (sensations of burning or pins and needles) than spasticity. It’s also sometimes prescribed off-label as an anti-anxiety drug and sleep aid.

Some side effects include:

  • sleepiness or fatigue
  • reduced white blood cell count
  • depression and anxiety
  • tremors
  • speech problems
  • vertigo, dry mouth
  • indigestion, nausea, and vomiting
  • diarrhea
  • changes in mood

Neurontin facts

How does it work?This medication blocks neurotransmitters and interrupts signals from the brain.
How do you take it?It’s taken as a tablet or capsule by mouth.
How often?Doses can be adjusted over time to help minimize side effects. In most cases, it can be taken up to three times per day.

Phenol is reserved for extreme cases of spasticity in those without control of their lower limbs, bowel, or bladder.

Once injected, the drug permanently blocks nerve function.

Phenol facts

How does it work?Phenol impairs the conduction of nerves and is used in cases of severe spasticity where other options have failed. It destroys nerve conduction permanently.
How do you take it?It’s injected into the intrathecal space within the spinal column.
How often?The effect is permanent and requires only one injection.

This medication may cause less muscle weakness than others used to treat spasticity, though it can still cause low blood pressure, nausea or vomiting, fever or chills, unusual tiredness, nervousness, and painful urination.

It is also used to treat spasticity caused by other diseases, including amyotrophic lateral sclerosis (ALS), spastic diplegia back pain, fibromyalgia, or injuries to the spine or central nervous system. It is also sometimes prescribed off-label as a sleep aid and for migraine or seizures.

Zanaflex facts

How does it work?It works by slowing action in the brain and nervous system to allow the muscles to relax.
How do you take it?It’s taken as a tablet or capsule either with or without food.
How often?The dosage is either two or three times per day.