Baclofen

Baclofen is a prescription medication used to treat Spasticity resulting from multiple sclerosis. 

• Baclofen is available under the following different brand names: Lioresal, Gablofen, Ozobax

Adult and pediatric dosage

Tablet

• 5mg (generic)
• 10mg (generic)
• 20mg (generic)

Oral solution

• 5mg/5mL (Ozobax)

Intrathecal solution, preservative free

• 500mcg/mL (generic, Lioresal, Gablofen)
• 1000mcg/mL (generic, Lioresal, Gablofen)
• 2000mcg/mL (generic, Lioresal, Gablofen)

Spasticity

Adult dosage

Orally

• 5 mg orally three times daily initially; after 3 days, may increase by 5 mg/dose every 3 days up to 20 mg orally three times daily
• May increase to a maximum of 80 mg/day (20 mg four times daily)

Intrathecal

• Screening phase: 50 mcg intrathecal by barbotage over 1 minute; if inadequate response within 8 hours, 75 mcg 24 hours later; if still inadequate, 100 mcg 24 hours later
• Patients who do not respond to 100 mcg intrathecal bolus should not be considered candidates for an implanted pump for chronic infusion

Titration (after initial 24 hours)

• Initial implant dose: 2 times screening dose that positive effect (or screening dose if effective lasted over 8 hours) administered over 24-hour period
• Spasticity of spinal cord origin: Increase by 10-30% every 24 hours until desired clinical effect 
• Spasticity of cerebral origin: Increase by 5-15% every 24 hours until desired clinical effect 

Maintenance

• Spasticity of spinal cord origin: Increase by 10-40% or decrease by 10-20% during periodic pump refills; usual range 300-800 mcg/day (not to exceed 1000 mcg/day)
• Spasticity of cerebral origin: Increase by 5-20% or decrease by 10-20% during periodic pump refills; usual range 90-700 mcg/day (not to exceed 1000 mcg/day)

Pediatric dosage

Oral

• Children younger than 12 years of age: Safety and efficacy not established. 
• Children 12 years of age or older: Initiate with a low dosage, preferably in divided doses orally
• Following suggested gradual increase dosage regimen based on clinical response and tolerability
• 5 mg orally three times daily initially; after 3 days, may increase by 5 mg/dose every 3 days up to 20 mg orally three times daily
• If necessary, may increase to a maximum of 80 mg/day (20 mg four times daily)

Intrathecal

Screening phase: 

• Test bolus: 50 mcg intrathecal by barbotage over 1 minute; if inadequate response within 8 hours, 75 mcg 24 hours later; if still inadequate, 100 mcg 24 hours later
• May start with 25 mcg dose for small patients
• Patient who do not respond to a 100 mcg intrathecal bolus should not be considered candidates for an implanted pump for chronic infusion

Titration (after initial 24 hours)

• Initial implant dose: 2 times screening dose that gave positive effect (or screening dose if effect lasted over 8 hours) administer over 24-hour period
• After the first 24 hours, the daily dose should be increased slowly by 5-15% only once every 24 hours, until desired clinical effect is achieved

Maintenance 

• Maintenance dose: Same as adult with spasticity of cerebral origin (average dose usually lower than adult)
• Increase by 5-20% or decrease by 10-20% during periodic pump refills
• Average daily dose for patients older than 12 years was 274 mcg/day, with a range of 24-1199 mcg/day

Dosage Considerations – Should be Given as Follows: 

• See "Dosages."

Common side effects of Baclofen include:

• drowsiness, 
• dizziness, 
• weakness, 
• tiredness, 
• headache, 
• trouble sleeping, 
• nausea, 
• increased urination, and 
• constipation

Serious side effects of Baclofen include:

• hives, 
• rash, 
• swelling in the face, tongue, and throat, 
• mood changes, 
• confusion, 
• depression, and
• hallucinations

Rare side effects of Baclofen include:

• none 

This is not a complete list of side effects and other serious side effects or health problems may occur as a result of the use of this drug. Call your doctor for medical advice about serious side effects or adverse reactions. You may report side effects or health problems to FDA at 1-800-FDA-1088.

If your medical doctor is using this medicine to treat your pain, your doctor or pharmacist may already be aware of any possible drug interactions and may be monitoring you for them.  Do not start, stop, or change the dosage of any medicine before checking with your doctor, health care provider or pharmacist first

• Baclofen has severe interactions with no other drugs.
• Baclofen has serious interactions with the following drugs:
  • benzhydrocodone/acetaminophen
  • calcium/magnesium/potassium/sodium oxybates
  • hydrocodone
  • metoclopramide intranasal
  • Selinexor
  • sodium oxybate
  • sufentanil SL
• Baclofen has moderate interactions with at least 154 other drugs.
• Baclofen has minor interactions with the following drugs:
  • eucalyptus
  • sage

This information does not contain all possible interactions or adverse effects. Visit the RxList Drug Interaction Checker for any drugs interactions. Therefore, before using this product, tell your doctor or pharmacist of all the products you use.  Keep a list of all your medications with you, and share this information with your doctor and pharmacist.  Check with your health care professional or doctor for additional medical advice, or if you have health questions, concerns.

Contraindications

• Hypersensitivity 
• Intrathecal use: IV, IM, SC or epidural administration 

Effects of drug abuse

• None

Short-Term Effects

• See “What Are Side Effects Associated with Using Baclofen?”

Long-Term Effects

• See “What Are Side Effects Associated with Using Baclofen?”

Cautions

• Use with caution in patients who have had a stroke; baclofen has not significantly benefited patients with stroke; patients have also shown poor tolerability to the drug
• Not indicated for spasm with rheumatic disease, stroke, Parkinson
• May take with food to avoid stomach upset
• Not significantly beneficial for patient with stroke
• Use with caution in seizure disorders and renal impairment
• Abrupt drug discontinuation has resulted in adverse reactions that include hallucinations, seizures, high fever, altered mental status, exaggerated rebound spasticity, and muscle rigidity, that in rare cases has advanced to rhabdomyolysis, multiple organ-system failure, and death
• May cause acute urinary retention that may be related to underlying disease; use caution in patients with urinary obstruction
• Animal studies have shown increased incidence in ovarian cysts; effect in humans inconclusive
• Use with caution in patients with decreased GI motility, peptic ulcer disease, and/or gastrointestinal obstructive disorders
• Use with caution in patients with a history of autonomic dysreflexia; presence of nociceptive stimuli or abrupt withdrawal may cause autonomic dysreflexia episode
• Possible exacerbation of psychotic disorders, schizophrenia or confusional state
• Neonatal withdrawal symptoms can occur; gradually reduce the dosage and discontinue oral baclofen before delivery
• Patients should avoid the operation of automobiles or other dangerous machinery until they know how the drug affects them; advise patients that the central nervous system effects may be additive to those of alcohol and other CNS depressants
• Use with caution in patients where spasticity is utilized to sustain upright posture and balance in locomotion or whenever spasticity is utilized to obtain increased function
• Intrathecal administration
  • Intrathecal used with implanted pump
  • Not for injection into pump catheter access port, as this may cause a life-threatening overdose
  • Delivery of more drug volume than the programmed rate (over infusion) can result in unexpected overdose, or withdrawal caused by early emptying of pump reservoir; refer to manufacturer's pump manual and instructions for refilling the reservoir
  • Potential for contamination due to non-sterile external surface of prefilled syringe; use of baclofen prefilled syringe in an aseptic setting (eg, operating room) to fill sterile intrathecal pumps prior to implantation in patients not recommended, unless external surface of prefilled syringe is treated to ensure sterility
  • Potentially life-threatening CNS depression, cardiovascular collapse, and/or respiratory failure
  • Resuscitative equipment and trained staff must be available during screening, dose titration, and refills
  • Intrathecal mass: Cases of intrathecal mass at the tip of the implanted catheter have been reported, most of them involving pharmacy-compounded analgesic admixtures; the most frequent symptoms associated with intrathecal mass include decreased therapeutic response (worsening spasticity, return of spasticity when previously well controlled, withdrawal symptoms, poor response to escalating doses, or frequent or large dosage increases), pain, and neurologic deficit/dysfunction
  • Inadvertent injection into the SC tissue can occur if the intrathecal reservoir refill septum is not properly accessed; SC injection may result in symptoms of a systemic overdose or early depletion of the reservoir
• Drug interaction overview
  • Baclofen may cause CNS depression, including drowsiness and sedation, which may be additive when used concomitantly with other CNS depressants or alcohol

Pregnancy and Lactation

• There are no adequate data on the developmental risk associated with the use in pregnant women.
• Clinical considerations
  • May increase the risk of late-onset neonatal withdrawal symptoms 
  • At recommended oral doses, baclofen is present in human milk
  • There are no human data on the effects of baclofen on milk production
  • There are no adequate data on the effects of baclofen on the breastfed infant
  • Withdrawal symptoms can occur in breastfed infants when maternal administration is stopped, or when breastfeeding is stopped
  • Consider developmental and health benefits of breastfeeding along with the mother’s clinical need and any potential adverse effects on the breastfed infant or from the underlying maternal condition