Baclofen (Oral)

Baclofen is a drug used to treat muscle spasms in patients who have conditions which affect their muscular control, such as MS or spinal damage.


Baclofen acts as an agonist to the GABA B receptors in the brain, similar to benzodiazepines, which can have similar relaxing effects. Baclofen was designed in 1966 by a Swiss scientist as a way to treat seizures and epilepsy. Since then, medical professionals have expanded the use of the drug to include other forms of muscle spasms.

Baclofen is sold under the brand name Lioresal (Novartis), as well in the generic form by a number of manufacturers.

Condition(s) Treated

  • Muscle spasms
  • Multiple Sclerosis
  • Spine damage
  • Epilepsy
  • Alcoholism (experimental, of 2017)

Type of Medicine

  • Muscle relaxant and antispastic.

Side Effects

Baclofen can cause a great number of different side effects in different patients. Not all of these side effects necessarily pose a risk to the patient, though. In many cases, the patient's body just needs time to adapt to the drug. Patients who experience the following side effects should check with their doctor if the side effects become especially difficult to deal with, or if they wish to know more about them:

  • Confusion
  • Dizziness/lightheadedness
  • Drowsiness
  • Nausea
  • Unusual weakness
  • Unusual muscle loss
  • Abdominal pain or discomfort
  • Clumsiness, unsteadiness, trembling, or other muscular problems
  • Constipation
  • Diarrhea
  • Painful or changed urinary patterns
  • Increased sense of wellbeing (baclofen can be anxiolytic)
  • Headache
  • Appetite loss
  • Decreased blood pressure
  • Muscle or join pain
  • Numbness in the extremities
  • Pounding or irregular heartbeat
  • Sexual dysfunction in males
  • Slurred speech
  • Stuffy nose
  • Swollen ankles
  • Unusual muscle stiffness
  • Unusual tiredness
  • Unusual weight gain

By far the most common side effect of baclofen is drowsiness, which as many as 63% of patients reported experiencing during clinical trials.

Baclofen can also produce unwanted effects in patients that can potentially be threatening. Patients should consult their doctor immediately if they experience any of the following side effects:

  • Bloody or discolored urine
  • Chest pain
  • Loss of consciousness
  • Hallucinations
  • New or worsening depression
  • Rogue mood changes
  • Phantom buzzing in the patient's ears
  • Rash or itchy skin

After a patient stops using baclofen, the body can react negatively to the absence of the drug. Patients should contact their doctor immediately if they experience any of the following after they stop taking baclofen:

  • Convulsions
  • Seizures
  • Increased muscle spasms or cramps
  • Mood or mental changes
  • New or worsening depression
  • Unusual nervousness, restlessness, or anxiety

This is not necessarily a complete list of side effects. Patients should contact their doctor if they experience any changes, physical or mental. Patients can report new side effects to the FDA at 1-800-FDA-1088 or at


Baclofen is usually available in 10 and 20 milligram tablets.

The optimum dosage for each patient is different. On average, the optimal dosage is between 40 and 80 milligrams of baclofen each day. Patients should take more than 80 milligrams of baclofen in a 24 hour period.

When patients first start taking baclofen, their dose builds slowly. The standard schedule go 5 milligrams of baclofen for 3 days, then 10 milligrams of baclofen for 3 days, then 15, and so forth until the patient has built up to a level which effectively treats their symptoms.

Patients are cautioned to use as little baclofen as is necessary to treat their symptoms. The less baclofen the patient is taking, the less likely they are to build a dependence, and the less chance they have of experiencing side effects.

If patients do not begin to see positive effects within a reasonable period, they are usually cautioned to begin to scale back off of the drug. Patients are advised not to simply stop taking baclofen cold turkey, as doing so may create withdrawal symptoms.


Baclofen can react negatively with drugs that will make the patient drowsy. These can include pain or cough reliever such as opioids or codeine, alcohol, marijuana, insomnia drugs like zolpidem (Ambien), anxiety drugs such as alprazolam (Xanax), antihistamines such as cetirizine, or other muscle relaxants such as cyclobenzaprine.

Baclofen can react negatively with a great number of drugs. Patients who are taking any of the following drugs should consult with their doctor before taking baclofen:

  • Acetaminophen
  • Alfentanil
  • Ammonium chloride
  • Anhydrous calcium oxide
  • Aspirin
  • Bromodiphenhydramine
  • Brompheniramine
  • Bupivacaine
  • Buprenorphine
  • Butorphanol
  • Carbinoxamine
  • Chlorcyclizine
  • Chlorpheniramine
  • Codeine
  • Dexbrompheniramine
  • Dexchlorpheniramine
  • Dezocine
  • Dihydrocodeine
  • Diphenhydramine
  • Droperidol
  • Fentanyl
  • Guaifenesin
  • Homatropine
  • Hydrocodone
  • Hydromorphone
  • Ibuprofen
  • Levomethadyl
  • Levorphanol
  • Meperidine
  • Methadone
  • Morphine
  • Nalbuphine
  • Naloxone
  • Naltrexone
  • Oxycodone
  • Oxymorphone
  • Pentazocine
  • Propoxyphene
  • Remifentanil
  • Ropivacaine
  • Sodium oxybate
  • Sufentanil
  • Tapentadol
  • Tramadol
  • AbobotulinumtoxinA
  • Acebutolol
  • Acetyl Carbromal
  • Acetylcarbromal
  • Aldesleukin
  • Alfuzosin
  • Aliskiren
  • Alprazolam (Xanax)
  • Aluminum hydroxide
  • Amiloride
  • Aminophylline
  • Amitriptyline
  • Amlodipine
  • Ammonium chloride
  • Amobarbital
  • Amoxapine
  • Amyl nitrite
  • Amylase
  • Apomorphine
  • Apraclonidine ophthalmic
  • Aripiprazole
  • Asenapine
  • Atenolol
  • Atropine
  • Azatadine
  • Belladonna
  • Benazepril
  • Bendroflumethiazide
  • Benzocaine
  • Benzthiazide
  • Benztropine
  • Bepridil
  • Betaxolol
  • Biperiden
  • Bisoprolol
  • Botulinum toxin type b
  • Brexpiprazole
  • Brimonidine ophthalmic
  • Brimonidine topical
  • Bivaracetam
  • Bromocriptine
  • Bumetanide
  • Buspirone
  • Butabarbital
  • Butalbital
  • Caffeine
  • Candesartan
  • Cannabis
  • Captopril
  • Carbamazepine
  • Carbetapentane
  • Carbidopa
  • Carbinoxamine
  • Cariprazine
  • Carisoprodol
  • Carteolol
  • Carvedilol
  • Cellulase
  • Cetrizine
  • Chlophendianol
  • Chlorpromazine
  • Chlorthalidone
  • Chloroxazone
  • Citalopram
  • Clemastine
  • Clevidipine
  • Clobazam
  • Clomipramine
  • Clonazepam (Klonopin)
  • Clonidine
  • Clorazepate
  • Clozapine
  • Conjugated estrogens
  • Cyclizine
  • Cyclobenzaprine
  • Cyproheptadine
  • Dantrolene
  • Deserpidine
  • Desflurane
  • Desipramine
  • Desvenlafaxine
  • Deutetrabenazine
  • Dextromethorpan
  • Diazepam
  • Diazoxide
  • Diltiazem
  • Dimenhydrinate
  • Divalproex sodium
  • Doxazosin
  • Doxepin
  • Doxylamine
  • Dronabinol
  • Droperidol
  • Duloxetine
  • Enflurane
  • Entacapone
  • Eplerenone
  • Eprosartan
  • Escitalopram
  • Eslicarbazepine
  • Esmolol
  • Estazolam
  • Eszopiclone
  • Ethacrynic acid
  • Ethanol
  • Ethchlorvynol
  • Ethosuximide
  • Ethotoin
  • Etomidate
  • Ezogabine
  • Felbamate
  • Felodipine
  • Fenoldopam
  • Flavoxate
  • Flibanserin
  • Fluoxetine
  • Fluphenazine
  • Flurazepam
  • Fluvoxamine
  • Fosinopril
  • Fosphenytoin
  • Fospropofol
  • Furosemide
  • Guanabenz
  • Guanadrel
  • Guanethidine
  • Guanfacine
  • Halazepam
  • Haloperidol
  • Halothane
  • Heroin
  • Hydralazine
  • Hydroflumethiazide
  • Hydroxyzine
  • Ifosfamide
  • Iloperidone
  • Imipramine
  • IncobotulinumtoxinA
  • Indapamide
  • Irbesartan
  • Isocarboxazid
  • Isoflurane
  • Isosorbide dinitrate
  • Isosorbide mononitrate
  • Isradipine
  • Kava
  • Ketamine
  • Labetalol
  • Lamotrigine
  • Levetiracetam
  • Levocetirizine
  • Levodopa
  • Lisinopril
  • Lithium
  • Lorazepam
  • Losartan
  • Loxapine
  • Lurasidone
  • Magnesium salicylate
  • Maprotiline
  • Meclizine
  • Mephenytoin
  • Mephobarbital
  • Meprobamate
  • Mesoridazine
  • Metaxalone
  • Methdilazine
  • Methocarbamol
  • Methohexital
  • Methotrimeprazine
  • Methoxyflurane
  • Methsuximide
  • Methyclothiazide
  • Metoclopramide
  • Metolazone
  • Metoprolol
  • Metyrosine
  • Mibefradil
  • Midazolam
  • Minoxidil
  • Mirtazapine
  • Moexipril
  • Molindone
  • Nabilone
  • Nadolol
  • Nebivolol
  • Nefazodone
  • Nicardipine
  • Nifedipine
  • Nimodipine
  • Nisoldipine
  • Nitroglycerin
  • Nitroprusside
  • Nitrous oxide
  • Nortiptyline
  • Olanzapine
  • Olmesartan
  • Olopatadine
  • OnabotulinumtoxinA (Botox)
  • Opium
  • Orphenadrine
  • Oxazepam
  • Oxcarbazepine
  • Paliperidone
  • Paraldehyde
  • Paramethadione
  • Paroxetine
  • Penbutolol
  • Pentobarbital
  • Perampanel
  • Pergolide
  • Perindopril
  • Perphenazine
  • Phenacemide
  • Phenelzine
  • Phenindamine
  • Phenobarbital
  • Phenoxybenzamine
  • Phensuximide
  • Phentolamine
  • Phenytoin
  • Pimozide
  • Pindolol
  • Polythiazide
  • Pramipexole
  • Prazosin
  • Pragabalin
  • Primidone
  • Prochlorperazine
  • Procyclidine
  • Promazine
  • Promethazine
  • Propiomazine
  • Propofol
  • Propranolol
  • Protriptyline
  • Pyrilamine
  • Quazepam
  • Quetiapine
  • Quinapril
  • Ramelteon
  • Ramipril
  • Rasagiline
  • Rauwolfia serpentina
  • Reserpine
  • Risperidone
  • Ropinirole
  • Rotigotine
  • Rufinamide
  • Secobarbital
  • Sertraline
  • Sevoflurane
  • Sibutramine
  • Silodosin
  • Sotalol
  • Spironolactone
  • St. John's Wort
  • Suvorextant
  • Tamsulosin
  • Tasimelteon
  • Telmisartan
  • Temazepam
  • Terazosin
  • Tetrabenazine
  • Thalidomide
  • Thiethylperazine
  • Thiopental
  • Thioridazine
  • Thiothixene
  • Tiagabine
  • Timolol
  • Tizanidine
  • Tolcapone
  • Topiramate
  • Torsemide
  • Trandolapril
  • Trandolapril / verapamil
  • Tranylcypromine
  • Trazodone
  • Triamterene
  • Triazolam
  • Trichlormethiazide
  • Trifluoperazine
  • Triflupromazine
  • Trihexyphenidyl
  • Trimeprazine
  • Trimethadione
  • Trimethaphan camsylate
  • Trimethobenzamide
  • Trimipramine
  • Tripelennamine
  • Triprolidine
  • Valbenazine
  • Valerian
  • Valproic acid
  • Valsartan
  • Venlafaxine
  • Verapamil
  • Vigabatrin
  • Zaleplon
  • Ziconotide
  • Ziprasidone
  • Zolpidem (Ambien)

This is not necessarily a complete list of medications that will interact with baclofen. Patients should inform their doctor of ALL medications, drugs, and supplements they are taking before considering taking baclofen. Patients should make sure that they are aware of all potential interactions between baclofen and drugs they are taking, and what the interactions may cause.


Baclofen is considered a class C pregnancy drug. Risk to the fetus or to a breastfeeding baby cannot be ruled out. Patients who are pregnant or who may become pregnant should consult their doctor before taking baclofen.

Patients who use baclofen for an extended period of time (multiple months of consecutive use) can build up a dependence on the drug. Patients who attempt to quit baclofen cold turkey or otherwise scale back their use of the drug may experience withdrawal symptoms, which can include:

  • Hallucinations (tactile, auditory, and visual)
  • Delusions
  • Confusion
  • Agitation
  • Delirium
  • Disorientation
  • Insomnia
  • Dizziness
  • Loss of consciousness
  • Nausea
  • Anxiety
  • Depersonalization
  • Tremors
  • Seizures
  • Psychosis
  • Mania
  • Changes in behavior
  • Changes in mood

In spite of its' similarity to benzodiazepines, baclofen at any dose rarely has a euphoric effect on the patient. As a result, there is limited potential for baclofen abuse, and the drug is not scheduled.

In rare cases, patients have reported experiencing an allergic reaction to baclofen. Patients should contact their doctors immediately if they experience any symptoms of an allergic reaction, including:

  • Rash
  • Itching or swelling of the face
  • Dizziness
  • Difficulty breathing

Baclofen can make patients drowsy and/or dizzy. As a result, patients should use caution when driving, operating heavy machinery, or performing any other activity which requires concentration.

Both baclofen and alcohol act on the GABA receptors in the brain. As a result, baclofen and alcohol can intensify the effects of one another on a patient who is using both drugs concurrently. Patients on baclofen should avoid consuming alcohol while they have baclofen in their system. Those that do may find themselves with a severely decreased tolerance and more at risk of blacking out, among other potential effects.

Patients with renal dysfunction should exercise caution when considering taking baclofen. Baclofen is removed from the body via the kidneys, so patients with damage or less efficient kidneys may have baclofen build up in their bodies, increasing the effects of baclofen and increasing the potential side effects they may experience. Patients with renal dysfunction should talk with their doctor before taking baclofen.

Patients with autonomic dysreflexia should exercise caution when considering taking baclofen. Baclofen itself, or the sudden cessation of taking baclofen can cause an episode of dysreflexia in the affected patient. Patients with autonomic dysreflexia should talk with their doctor about the potential risks of the drug before taking baclofen.

Patients with psychosis, schizophrenia, depression, or any other mental disorder should exercise caution when considering taking baclofen. Baclofen has been known to cause mood and behavioral effects in patients, especially in patients with preexisting conditions. Patients with mental illnesses should discuss the potential risks with their doctor, as well as potential alternatives to baclofen.

Patients with seizure disorders have reported experiencing worse seizures and diminished control during seizures while taking baclofen. Additionally, baclofen withdrawal can greatly increase the risk of seizures, especially in patients who are predisposed towards them (seizures). Patients who suffer from seizures or who have a history of suffering from seizures should consult with their doctor about whether or not baclofen is right for them.

Patients should be careful to take the dose prescribed to them. Baclofen overdose is possible, and symptoms can include:

  • style="text-align: left;">Muscle weakness
  • Vomiting
  • Loss of consciousness
  • Drowsiness
  • Dilated pupils
  • Respiratory depression
  • Seizures
  • Drowsiness

Patients should contact their doctor immediately if they experience any of the above symptoms, especially if they are aware that they deviated from their prescribed dose.



Baclofen tablets should be stored at a room temperature of between 68 and 75 degrees Fahrenheit.

Baclofen tablets which have been split should be taken within two weeks to ensure optimal strength.


Baclofen is a potent drug that in the right patient can offer a great deal of relief. Some patients, though, may be put off by its' psychoactive effects. Baclofen's capacity to affect mood and mental state, especially in those that are already mentally ill, means that patients should consider strongly whether or not baclofen is right for them. Patients should bear in mind that medicine is intended to help the patient, and that if it does more harm than good, then there is no reason for the patient to take it.

Last Reviewed:
December 23, 2017
Last Updated:
April 02, 2018
Content Source: