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Baclofen (By injection)

Baclofen (BAK-loe-fen)

Treats muscle spasms. This medicine is a muscle relaxer.

Brand Name(s):

Gablofen, Lioresal Intrathecal, Lioresal Intrathecal Refill Kit

There may be other brand names for this medicine.

When This Medicine Should Not Be Used:

This medicine is not right for everyone. Do not use it if you had an allergic reaction to baclofen.

How to Use This Medicine:


  • Your doctor will prescribe your exact dose. Your dose may need to be changed several times in order to find out what works best for you. This medicine is given through a needle directly into your spinal cord.
  • You will first be given 1 or 2 test doses, to see if this medicine will work for you. A nurse or other trained health professional will give you this test dose in a clinic or hospital. You will need to stay for 4 to 8 hours to make sure the medicine does not cause any problems.
  • If your muscle spasms get better with the test dose, you may be able to start using this medicine all the time. You will need to have a pump placed under your skin, which will pump medicine directly into your back all day.
  • This medicine should come with a Medication Guide. Ask your pharmacist for a copy if you do not have one.
  • Your family or other caregivers need to know how to use your pump and medicine. Make sure you and your caregivers all know these 3 things: (1) Signs that you are getting too much or too little medicine. (2) What to do if you have any of these signs. (3) How to care for the pump and the needle that is placed in your back.
  • Missed dose: You must use this medicine on a fixed schedule. Call your doctor or pharmacist if you miss a dose.

Drugs and Foods to Avoid:

Ask your doctor or pharmacist before using any other medicine, including over-the-counter medicines, vitamins, and herbal products.

  • Some medicines can affect how baclofen works. Tell your doctor if you use anything else that makes you sleepy. Some examples are allergy medicine, narcotic pain medicine, and alcohol.

Warnings While Using This Medicine:

  • Tell your doctor if you are pregnant or breastfeeding, or if you have kidney disease or any kind of infection. Tell your doctor if you used baclofen before, and if you had problems when you stopped using it.
  • Ask your doctor for an Emergency Card listing the symptoms that may happen if you get too much or too little medicine. Carry the card with you at all times. Learn what the pump alarm sounds like and what to do if the alarm goes off.
  • Do not stop taking this medicine suddenly without asking your doctor. You may need to decrease your dose slowly before you stop taking it completely.
  • Your doctor will need to check your progress at regular visits while you are using this medicine. Be sure to keep all appointments.
  • This medicine may make you dizzy or drowsy. Do not drive or do anything that could be dangerous until you know how this medicine affects you.
  • Keep all medicine out of the reach of children. Never share your medicine with anyone.

Possible Side Effects While Using This Medicine:

Call your doctor right away if you notice any of these side effects:

  • Allergic reaction: Itching or hives, swelling in your face or hands, swelling or tingling in your mouth or throat, chest tightness, trouble breathing
  • Decrease in how much or how often you urinate
  • Fainting, shallow breathing, seizures
  • High fever, increased muscle spasms or stiffness, confusion, lightheadedness, numbness, tingling
  • Muscle weakness
  • Pain, redness, or swelling around the pump or needle
  • Unusual sleepiness, tiredness, or lightheadedness

If you notice these less serious side effects, talk with your doctor:

  • Agitation, mild headache
  • Nausea, vomiting, constipation

If you notice other side effects that you think are caused by this medicine, tell your doctor

Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088

Last Updated: 5/1/2020

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