Baclofen

Pronunciation: BAK-loh-fen.

Generic name
baclofen
Drug class
Skeletal muscle relaxant; GABA-B receptor agonist (antispastic agent)
Form
Tablet (10 mg, 20 mg), oral solution (5 mg/5 mL); intrathecal injection solution (50 mcg/mL, 500 mcg/mL, 2000 mcg/mL) for pump use
Route
Oral (tablet, oral solution); intrathecal injection via implanted pump (specialist use only, for severe spasticity)
Legal status
Prescription-only medicine

Availability and supply rules vary by country

Trade names by country: United States · United Kingdom · Canada · Australia · New Zealand

Australia: Lioresal (6), Generic baclofen products (6) · Full directory

What baclofen is and how it works

Baclofen is a muscle relaxant that reduces spasticity (severe muscle tightness and spasms) by acting on GABA-B receptors in the spinal cord. It is used mainly for spasticity caused by multiple sclerosis or spinal cord disease, and is available as oral tablets/solution or, for severe cases, as a continuous intrathecal infusion delivered by an implanted pump. (1) (2)

A genuine and important safety issue with baclofen, in either form, is that stopping it suddenly can cause a serious withdrawal reaction -- including hallucinations, seizures, high fever, and, in rare cases, life-threatening complications. Baclofen should always be stopped gradually, under your clinician's direction, never abruptly on your own. If you have the intrathecal (pump) form, keeping your scheduled refill appointments is especially important, since pump or catheter problems can cause the same dangerous withdrawal if the medicine stops reaching you unexpectedly.

Mechanism of action: how baclofen works

Baclofen is a GABA-B receptor agonist that acts primarily at the spinal cord level, inhibiting excitatory neurotransmitter release from afferent nerve terminals and reducing the excitability of interneurons, which decreases muscle tone and spasm frequency. (1) (2)

What baclofen is used for

Spasticity from multiple sclerosis

Used to relieve spasticity from multiple sclerosis, particularly for flexor spasms, associated pain, clonus (rhythmic muscle contractions), and muscular rigidity. (1)

Spasticity from spinal cord disease or injury

May also help spasticity from spinal cord injury or other spinal cord diseases (infectious, degenerative, traumatic, neoplastic, or of unknown origin), and muscle spasm of cerebral origin. (1) (7)

Severe spasticity (intrathecal/pump form)

The intrathecal (pump-delivered) form is used for severe spasticity that has not responded well enough to oral baclofen or other oral antispastic medicines, delivering the medicine directly into the fluid around the spinal cord. (2)

Before taking baclofen

Do not take / not appropriate for

  • Do not take baclofen if you have a known allergy to it. (all countries, both forms) (1) (2)
  • The intrathecal (pump) form must never be given by vein, into a muscle, under the skin, or into the epidural space -- it is specifically for intrathecal (spinal fluid) delivery via the approved pump system only. (all countries (intrathecal form)) (2)
  • Do not stop taking baclofen suddenly, or skip an intrathecal pump refill appointment, without your clinician's direct guidance -- this is not a simple precaution but a genuine, serious safety risk. (all countries, both forms) (1) (2)

Tell your clinician about

  • Any history of epilepsy or seizures.
  • Any history of alcohol use disorder, depression, or previous suicide attempts -- baclofen has a recognised (though uncommon) association with suicide and suicide-related events, particularly in people with these risk factors.
  • Any history of substance misuse, since baclofen misuse, abuse, and dependence have been reported, particularly with off-label high-dose use.
  • If you have an intrathecal pump: any signs of pump malfunction, or if you have ever missed a scheduled refill.
  • Whether you are pregnant, planning pregnancy, or breastfeeding.
  • Any kidney problems, since baclofen is cleared by the kidneys.
(1) (2) (6) (7)

How to take baclofen

  • Take oral baclofen exactly as prescribed; your clinician will start at a low dose and increase it gradually.
  • If you use the intrathecal (pump) form, it is programmed and refilled only by your specialist team -- there is nothing for you to adjust yourself.
  • If your clinician decides to stop baclofen, the dose is reduced gradually over time -- never stop abruptly on your own, even if you feel well.
  • Keep every scheduled intrathecal pump refill appointment -- missing one can cause the same dangerous withdrawal as stopping abruptly.
(1) (2)

Procedures and treatment changes

Tell the treating team before surgery, procedures, or any medicine change. Do not alter treatment without the responsible clinician. (1) (2) (3) (4) (5) (6) (7)

Missed dose

If you miss an oral dose, contact your clinician or pharmacist for guidance rather than doubling the next dose. If you have an intrathecal pump and think you may have missed or will miss a scheduled refill, contact your specialist team immediately -- this is time-sensitive because of the withdrawal risk.

Overdose

Seek emergency medical help immediately for a suspected overdose. Symptoms can include severe drowsiness, muscle weakness, breathing difficulty, seizures, or loss of consciousness, and can be life-threatening, especially with the intrathecal form or at high off-label doses. (1) (6)

Side effects

Side effects and their urgency vary; report severe, persistent, or concerning symptoms.

Drowsiness and sedation.

What to notice: Drowsiness and sedation.

What to do: Discuss persistent or troublesome symptoms with the treating clinician or pharmacist. (1)

Dizziness and weakness.

What to notice: Dizziness and weakness.

What to do: Discuss persistent or troublesome symptoms with the treating clinician or pharmacist. (1)

Nausea.

What to notice: Nausea.

What to do: Discuss persistent or troublesome symptoms with the treating clinician or pharmacist. (1)

Confusion, particularly at higher doses or in older adults.

What to notice: Confusion, particularly at higher doses or in older adults.

What to do: Discuss persistent or troublesome symptoms with the treating clinician or pharmacist. (1)

Serious warnings

Signs of withdrawal after stopping or reducing baclofen too quickly, or after a missed intrathecal pump refill — high_alert_non_boxed_for_oral_form_boxed_warning_for_intrathecal_form

Symptoms: Hallucinations, seizures, a high fever, sudden confusion, worsening muscle stiffness or spasms, or muscle rigidity.

Action: Seek emergency medical help immediately. For oral baclofen, this genuine risk is described in the medicine's warnings section; for the intrathecal (pump) form, this same withdrawal syndrome is described in an actual FDA boxed warning, reflecting how quickly and seriously it can progress -- in rare cases to rhabdomyolysis (muscle breakdown), multiple organ failure, and death. Baclofen must always be tapered down gradually by a clinician, and intrathecal pump refill appointments must never be missed. (1) (2)

New or worsening thoughts of suicide or self-harm — regulator_confirmed_serious_warning

Symptoms: New or worsening depression, hopelessness, or thoughts of harming yourself.

Action: Tell a clinician or seek urgent help immediately (or contact a crisis line). Suicide and suicide-related events have been reported in people taking baclofen, particularly those with alcohol use disorder, depression, or a past suicide attempt. (6) (7)

Signs of baclofen overdose or dangerous dose escalation — high caution

Symptoms: Extreme drowsiness, slowed or difficult breathing, severe muscle weakness, or loss of consciousness.

Action: Seek emergency medical help immediately. This risk is highest with the intrathecal form and with off-label high-dose oral use (for example, for alcohol dependence), which regulators have specifically cautioned about after fatal overdoses. (6)

Signs of a serious allergic reaction — emergency

Symptoms: Swelling of the face, lips, tongue, or throat; difficulty breathing; widespread rash or hives.

Action: Seek emergency medical help immediately. (1)

Interactions

  • Other sedating medicines, alcohol, and other CNS depressants can add to baclofen's drowsiness and sedative effects. (1)
  • Medicines that lower the seizure threshold may need extra caution, since baclofen has been associated with deterioration in seizure control in some patients. (1)

Pregnancy, breastfeeding, kidney/liver function, age

Pregnancy

Discuss with your clinician; use in pregnancy requires individualised specialist assessment. (1) (2) (3) (4) (5) (6) (7)

Children

Not specifically established for the oral solution product reviewed in this dossier for young children; the intrathecal form is used in appropriately selected pediatric patients under specialist care. Confirm the specific product's approved age range with your clinician. (1) (2) (3) (4) (5) (6) (7)

Elderly

Older adults may be more sensitive to sedation, confusion, and weakness; dose increases are usually more gradual and closely monitored. (1) (2) (3) (4) (5) (6) (7)

Hepatic_impairment

Not specifically quantified in the sources reviewed for this dossier; use with caution and clinician guidance. (1) (2) (3) (4) (5) (6) (7)

Renal_impairment

Baclofen is cleared by the kidneys, so dose adjustment and closer monitoring are generally needed in reduced kidney function; discuss with your clinician. (1) (2) (3) (4) (5) (6) (7)

Source_ids

US-DAILYMED-BACLOFEN-ORAL-SOLUTION-2026,US-DAILYMED-LIORESAL-INTRATHECAL-2026 (1) (2) (3) (4) (5) (6) (7)

Monitoring

Before starting

  • Review of seizure history
  • Review of alcohol use, depression, or prior suicide attempts
  • Review of kidney function
  • For the intrathecal form: careful patient selection and a supervised screening test dose

During treatment

  • Watch for early signs of withdrawal (increased spasticity, anxiety, itching) if any dose is missed or reduced.
  • For the intrathecal form: pump alarms, scheduled refill visits, and monitoring for signs of pump or catheter malfunction are essential.
  • Monitoring for mood changes or thoughts of self-harm, especially in patients with known risk factors.
(2) (6)

Storage

Store tablets/solution at room temperature, protected from light and moisture, out of reach of children. Intrathecal solution is stored and handled according to the specific product's instructions by the healthcare team.

Professional information

Clinician-facing context only, sourced from the current US FDA prescribing information for both oral baclofen and Lioresal Intrathecal, plus UK/Ireland-EU and Australia/New Zealand regulator sources reviewed for this dossier; verify against the current full label before prescribing.

United States / United Kingdom / European Union / Canada / Australia / New Zealand

Indication: Oral -- spasticity (multiple sclerosis, spinal cord disease)

Dose summary: Initial 5 mg three times daily, titrated gradually; usual maximum 80 mg/day; tapered gradually on discontinuation, never stopped abruptly.

Renal context: Baclofen is renally cleared; dose reduction and caution needed with reduced renal function. (1)

United States (and consistent with UK/EU intrathecal licensing)

Indication: Intrathecal -- severe spasticity via implanted pump

Dose summary: Individualised screening then maintenance dosing (commonly 300-800 mcg/day spinal origin; 90-703 mcg/day cerebral origin); carries a genuine FDA boxed warning for abrupt-discontinuation withdrawal syndrome, distinct from the oral form's warnings-section framing.

Renal context: Not specifically quantified in the sources reviewed for this dossier. (2) (3)

Mechanism of action

Hepatic guidance

Not specifically quantified in the sources reviewed for this dossier.

Overdose note

No specific antidote; manage with supportive care, airway protection, and close monitoring, particularly for respiratory depression and seizures; overdose risk is heightened with the intrathecal form and with off-label high-dose oral use. (1) (2)

Frequently asked questions

Why can't I just stop taking baclofen if I feel better?

Because stopping baclofen suddenly -- whether the oral or intrathecal form -- can trigger a genuine, serious withdrawal reaction, including hallucinations, seizures, high fever, and in rare cases life-threatening complications. Your clinician will always taper the dose down gradually rather than stopping it abruptly. (1) (2)

Is the withdrawal warning a 'boxed warning' for all forms of baclofen?

No -- this is a genuine, verified difference. For oral baclofen (tablets and solution), the withdrawal risk is described in a standard warnings section of the US label. For Lioresal Intrathecal (the pump-delivered form), the same withdrawal syndrome is described in an actual FDA boxed warning, the strongest safety warning the FDA uses, reflecting the added risk from unexpected pump or catheter problems. (1) (2)

Is there a suicide risk with baclofen?

Regulators in Australia and New Zealand have identified reports of suicide and suicide-related events in people taking baclofen, particularly those with alcohol use disorder, depression, or a past suicide attempt. If you or someone you know taking baclofen develops new or worsening low mood or thoughts of self-harm, seek help promptly. (6) (7)

What is the mechanism of action of baclofen?

Baclofen is a GABA-B receptor agonist that acts primarily at the spinal cord level, inhibiting excitatory neurotransmitter release from afferent nerve terminals and reducing the excitability of interneurons, which decreases muscle tone and spasm frequency. (1) (2)

What is the generic name of Baclofen?

The generic name is baclofen. (1) (2)

What class of drug is baclofen?

Baclofen is classed as: Skeletal muscle relaxant; GABA-B receptor agonist (antispastic agent). (1) (2)

References

  1. Baclofen Oral Solution, 5 mg/5 mL -- full prescribing informationU.S. Food and Drug Administration / DailyMed (NIH), full prescribing information, Palmetto Pharmaceuticals Inc. · United States · accessed 2026-07-30 · source 1
  2. LIORESAL INTRATHECAL (baclofen injection) -- full prescribing informationU.S. Food and Drug Administration / DailyMed (NIH), full prescribing information · United States · accessed 2026-07-30 · source 2
  3. Lioresal Intrathecal Infusion and generic baclofen infusion -- Summary of Product Characteristicselectronic medicines compendium (emc), United Kingdom · United Kingdom · accessed 2026-07-30 · source 3
  4. Lioresal 10 mg Tablets -- HPRA product licenceHealth Products Regulatory Authority (HPRA), Ireland · Ireland (European Union) · accessed 2026-07-30 · source 4
  5. BACLOFEN Tablets 10 mg and 20 mg -- Product MonographHealth Canada product monograph · Canada · accessed 2026-07-30 · source 5
  6. Use caution when prescribing baclofen off label -- TGA safety update, plus Lioresal product informationTherapeutic Goods Administration (TGA), Australia · Australia · accessed 2026-07-30 · source 6
  7. Baclofen (Noumed) -- New Zealand Data Sheet and Consumer Medicine InformationMedsafe (New Zealand regulator) · New Zealand · accessed 2026-07-30 · source 7

Brand names by country

Single-ingredient baclofen names are shown separately by country. Product availability, strengths, and supply rules can change; combination products are not included here.

Priority countries

United States

  • Gablofen2000 ug/mL, 500 ug/mL, 50 ug/mL, 1000 ug/mL · piramal critical care inc
  • LYVISPAH20 mg, 5 mg, 10 mg · amneal pharmaceuticals llc
  • Baclofen (Intrathecal)500 ug/mL, 2000 ug/mL · maia pharmaceuticals, inc.
  • OZOBAX DS10 mg/5mL · rosemont pharmaceuticals llc
  • Lioresal (baclofen).05 mg/mL · amneal pharmaceuticals llc
  • FLEQSUVY5 mg/mL · azurity pharmaceuticals, inc.

United Kingdom

  • Lioresal Tablets (3)MHRA licensed confirmed · 10 mg · Novartis (originator); generics also available
  • Lioresal Intrathecal Infusion (3)MHRA licensed emc smpc confirmed · 10 mg/5 mL, 10 mg/20 mL · Novartis

Canada

  • LIORESAL INTRATHECAL
  • VAL-BACLOFEN INTRATHECAL
  • LIORESAL
  • LIORESAL D.S.

Australia

  • Lioresal (6)TGA approved confirmed · not specified in source · Novartis Pharmaceuticals Australia
  • Generic baclofen products (6)TGA approved confirmed · not specified in source · Multiple sponsors

New Zealand

  • Baclofen (Noumed) (7)Medsafe registered confirmed · not specified in source · Noumed
View brands in additional countries.

European Union

Lioresal 10 mg Tablets (Ireland) (4)