Key points about baclofen

  • Baclofen is used to treat muscle spasms.
  • Baclofen is also called Pacifen.
  • Find out how to take it safely and possible side effects. 
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Baclofen is a muscle-relaxant medication used for the treatment of severe muscle spasm (spasticity). It is often used in adults and children with cerebral palsy or other conditions that affect the brain or spinal cord, including multiple sclerosis or spinal cord injury. Baclofen is also known as Pacifen.

Read more about cerebral palsy and multiple sclerosis.

In Aotearoa New Zealand, baclofen is available as 10 mg tablets or liquid (1 mg in 1 mL).

  • The dose of baclofen is different for different people.
  • The starting dose of baclofen is 5 mg (milligrams) 3 times a day.
  • Depending on how your body responds to this dose, your doctor may increase it. The maximum dose depends on how you respond to baclofen and your condition (why you are taking it).
  • Always take your baclofen exactly as your doctor has told you. The pharmacy label on your medicine will tell you how much baclofen to take, how often to take it, and any special instructions.
  • You should start to feel the effect of baclofen after taking it regularly for 3–4 days. It may take up to 10 days for you to get the maximum effect.

  • Timing: Take your baclofen at the same times each day. Take baclofen with or just after food.
  • Missed dose: If you forget to take your dose, take it as soon as you remember. But, if it is nearly time for your next dose, just take the next dose at the right time. Do not take two doses at the same time or very close together.
  • Tablets: Swallow tablets whole with a full glass of water, juice or something similar. If your dose means you need to take a part of a tablet, you should split the tablet with a tablet cutter.
  • Liquid: If you are using baclofen liquid, it is important that you know how to measure your dose accurately. To measure out the amount accurately, ensure you have an appropriate dose measure – medicine spoon or medicine syringe. Check with your Pharmacist if you're unsure of how much to take or how to measure your dose.
  • Keep taking baclofen regularly. Do not stop taking baclofen without talking to your doctor. Stopping baclofen suddenly may cause your condition to worsen or may cause unwanted side effects such as mood changes and fast heart beat.

Here are some things to know when you're taking baclofen. Other things may be important as well, so ask your healthcare provider what you should know about.

Other medicines: Baclofen may interact with some medications, herbal supplements and rongoā Māori, so check with your doctor or pharmacist before starting baclofen and before starting any new products.

Like all medicines, baclofen can cause side effects, although not everyone gets them. Often side effects improve as your body gets used to the new medicine. Let your doctor know if any of these things happen to you as your dose or your treatment may need to be adjusted.

Side effects What should I do?
  • Seizures
  • Tell your doctor immediately.
  • Confusion
  • Weakness
  • Tell your doctor.
  • Feeling sleepy or lightheaded
  • Tell your doctor.
  • Do not drive or use tools.
  • Avoid drinking alcohol.
  • Feeling tired
  • Headache
  • Difficulty sleeping or nightmares
  • Peeing (urinating) more often
  • Nausea (feeling sick)
  • Constipation (finding it hard to poo)
  • Tell your doctor if these bother you.
Did you know that you can report a side effect to a medicine to CARM (Centre for Adverse Reactions Monitoring)? Report a side effect to a product(external link)

5 questions to ask about your medications(external link) Health Quality and Safety Commission, NZ, 2019

English(external link)
Te reo Māori(external link)

The following links provide more information on baclofen.

Baclofen(external link) NZ Formulary Patient Information
Baclofen for muscle spasm(external link) Medicines for Children Patient Information
Pacifen tablets(external link) Medsafe Consumer Information Leaflet


Baclofen(external link) NZ Formulary
Pacifen tablets(external link) Medsafe Product Datasheet
Baclofen oral liquid medication alert(external link) Health Quality and Safety Commission NZ, October 2021

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Credits: Maya Patel, Pharmacist, Healthify He Puna Waiora. Healthify is brought to you by Health Navigator Charitable Trust.

Reviewed by: Sandra Ponen, Pharmacist

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