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What is baclofen?

Baclofen is a skeletal muscle relaxant used to treat muscle symptoms caused by multiple sclerosis (MS), including spasm, pain, and stiffness. It is classified as an antispastic agent. It inhibits both monosynaptic (single) and polysynaptic (multiple interwoven) reflexes at the spinal level. Baclofen is indicated for the relief of flexor spasms, clonus (spasms with rhythmic contractions), and muscular rigidity.

How does baclofen work?

Baclofen inhibits nerve reflex signaling in the spine and other nerve sites to reduce or eliminate spasm. The exact mechanism by which baclofen works to control spasticity is not known.

How do people with MS use baclofen to manage symptoms?

Baclofen is generally taken by mouth. For the best effect, oral baclofen is usually given at a daily, divided dose of between 40 and 80 mg. However, it must be started at a low dosage (5 mg) and gradually increased in increments of 5 mg over the course of several weeks. Patients who require more than an 80 mg oral baclofen daily dose may be candidates for intrathecal baclofen pump. Talk to your doctor for more information.

What are the brand names for baclofen?

Baclofen is sold under several different brand names in the US, including but not limited to:

  • Lioresal
  • Lioresal Intrathecal
  • Gablofen

Baclofen is most often taken as a tablet by mouth. Tablets come in 10 or 20 mg dosages. It is also available as an injection, branded as Gablofen and Lioresal Intrathecal, formulated for intrathecal infusion, a method to deliver medication into the spinal fluid by an implantable pump.

What are the potential side effects of baclofen?

Taking baclofen can cause side effects for some people. The most common ones are:

  • Drowsiness
  • Dizziness
  • Weakness
  • Fatigue
  • Confusion
  • Headache
  • Insomnia (difficulty sleeping)
  • Low blood pressure
  • Nausea
  • Constipation
  • Urinary frequency
  • Impaired reaction time, some people should be advised to refrain from driving or operating heavy machinery.

If any of these side effects are severe or won’t go away, it’s important to contact your healthcare provider immediately. When discontinuing baclofen gradually reduce the dose. If you stop taking baclofen abruptly, there is a risk of hallucination and seizures.

Baclofen should be used with caution in people with MS who:

  • Have impaired kidney function
  • Have had a stroke
  • Are children under the age of 12
  • Are pregnant, unless the benefit clearly outweighs potential risk to the fetus
  • Use alcohol and other CNS depressants as the effects may be compounded

Patients should talk to their healthcare professional about other medications they are taking, possible side effects and any other medical condition they have before starting baclofen.

Written by Linda Saxl Minton | Last review date: July 2019.
  1. Baclofen prescribing information available at: Accessed 4/14/18.