Baclofen 20mg Tablets
It is used to treat spasms in patients with MS (multiple sclerosis) or spinal cord problems.It may be given to you for other reasons. Talk with the doctor.
Drug Class
Skeletal Muscle Relaxant, Antispasticity Agent
Pharmacologic Class
GABA-B Receptor Agonist
Pregnancy Category
Category C
FDA Approved
Aug 1977
DEA Schedule
Not Controlled
Overview
What is this medicine?
Baclofen is a medication used to relax muscles and relieve muscle spasms, stiffness, and pain caused by conditions like multiple sclerosis or spinal cord injury. It works by calming overactive nerves in the spinal cord.
How to Use This Medicine
Taking Your Medication
To use this medication correctly, follow your doctor's instructions and read all the information provided. Take your medication as directed, with or without food.
Storing and Disposing of Your Medication
Store your medication at room temperature in a dry place, avoiding bathrooms. If you split your tablets, be aware that they may have a limited storage time. Check with your pharmacist to determine how long you can safely store the split tablets. Keep all medications in a secure location, out of reach of children and pets.
Missing a Dose
If you miss a dose, take it as soon as you remember. However, if it's close to the time for your next scheduled dose, skip the missed dose and resume your regular dosing schedule. Do not take two doses at the same time or take extra doses to make up for a missed one.
To use this medication correctly, follow your doctor's instructions and read all the information provided. Take your medication as directed, with or without food.
Storing and Disposing of Your Medication
Store your medication at room temperature in a dry place, avoiding bathrooms. If you split your tablets, be aware that they may have a limited storage time. Check with your pharmacist to determine how long you can safely store the split tablets. Keep all medications in a secure location, out of reach of children and pets.
Missing a Dose
If you miss a dose, take it as soon as you remember. However, if it's close to the time for your next scheduled dose, skip the missed dose and resume your regular dosing schedule. Do not take two doses at the same time or take extra doses to make up for a missed one.
Lifestyle & Tips
- Avoid driving or operating heavy machinery until you know how this medication affects you, as it can cause drowsiness and dizziness.
- Avoid alcohol and other CNS depressants (e.g., sedatives, tranquilizers, opioids) while taking baclofen, as this can increase drowsiness and other side effects.
- Do not stop taking baclofen suddenly, especially if you have been on it for a long time or at high doses. Abrupt discontinuation can lead to severe withdrawal symptoms. Your doctor will guide you on how to slowly reduce the dose.
- Take baclofen with food or milk if it causes stomach upset.
- Report any new or worsening side effects to your doctor.
Available Forms & Alternatives
Available Strengths:
- Baclofen 10mg Tablets
- Baclofen 20mg Tablets
- Baclofen 40mg/20ml Inj, 20ml
- Baclofen 5mg Tablets
- Baclofen 20mg/20ml Inj 20ml
- Baclofen 10mg/20 Inj, 20ml
- Baclofen 5mg/5ml Solution
- Baclofen 50mcg/ml Pf Syr, 1ml
- Baclofen 25mg/5ml Oral Susp 300ml
- Baclofen 25mg/5ml Oral Susp 120ml
- Baclofen 15mg Tablets
- Baclofen 25mg/5ml Oral Susp 250ml
- Baclofen 2000mcg Inj Refill Kit
Dosing & Administration
Adult Dosing
Standard Dose:
Initial 5 mg orally three times daily, titrated every 3 days by 5 mg per dose up to a maximum of 20 mg three times daily (60 mg/day). Some patients may require up to 80 mg/day (20 mg four times daily).
Dose Range:
15 - 80 mg
Condition-Specific Dosing:
spasticity:
Initial 5 mg TID, gradually increase by 5 mg increments every 3 days as needed, up to 20 mg TID-QID (max 80 mg/day).
Pediatric Dosing
Neonatal:
Not established
Infant:
Not established
Child:
Initial 0.3 mg/kg/day in 4 divided doses. Titrate slowly based on response and tolerability. Max 2 mg/kg/day or 60 mg/day, whichever is less. (Use in children is often off-label and requires careful titration).
Adolescent:
Initial 0.3 mg/kg/day in 4 divided doses. Titrate slowly based on response and tolerability. Max 2 mg/kg/day or 60 mg/day, whichever is less. (Often treated as adult dosing once weight/age appropriate).
Dose Adjustments
Renal Impairment:
Mild:
No specific adjustment for mild impairment, but monitor for increased side effects.
Moderate:
Reduce initial dose by 50% (e.g., 2.5 mg TID) and titrate very cautiously. Monitor closely for adverse effects.
Severe:
Avoid use if possible. If necessary, reduce initial dose significantly (e.g., 2.5 mg once daily or every other day) and titrate with extreme caution. Monitor closely for toxicity.
Dialysis:
Baclofen is dialyzable. Administer dose after dialysis. Avoid chronic use in ESRD due to accumulation and prolonged effects.
Hepatic Impairment:
Mild:
No specific adjustment needed.
Moderate:
No specific adjustment needed.
Severe:
No specific adjustment needed. Baclofen is minimally metabolized by the liver.
Pharmacology
Mechanism of Action
Baclofen is a gamma-aminobutyric acid (GABA) derivative that acts as a GABA-B receptor agonist. It is thought to exert its effects by hyperpolarizing afferent terminals, thereby inhibiting both monosynaptic and polysynaptic reflexes at the spinal cord level. This action reduces the release of excitatory neurotransmitters, leading to a decrease in muscle spasticity and associated pain.
Pharmacokinetics
Absorption:
Bioavailability:
70-85%
Tmax:
2-3 hours
FoodEffect:
Minimal effect on absorption, can be taken with or without food.
Distribution:
Vd:
0.7 L/kg
ProteinBinding:
Approximately 30%
CnssPenetration:
Yes
Elimination:
HalfLife:
3-4 hours
Clearance:
Not available
ExcretionRoute:
Primarily renal (70-80% unchanged)
Unchanged:
70-80%
Pharmacodynamics
OnsetOfAction:
1-2 hours
PeakEffect:
3-4 hours
DurationOfAction:
4-6 hours
Safety & Warnings
Side Effects
Urgent Side Effects: Seek Medical Help Right Away
Although rare, some people may experience severe and potentially life-threatening side effects while taking this medication. If you notice any of the following symptoms, contact your doctor or seek immediate medical attention:
Signs of an allergic reaction, such as:
+ Rash
+ Hives
+ Itching
+ Red, swollen, blistered, or peeling skin with or without fever
+ Wheezing
+ Tightness in the chest or throat
+ Trouble breathing, swallowing, or talking
+ Unusual hoarseness
+ Swelling of the mouth, face, lips, tongue, or throat
Severe dizziness or fainting
Confusion
New or worsening mental, mood, or behavioral changes
Hallucinations (seeing or hearing things that are not there)
Seizures
Changes in balance or coordination
Changes in vision
Chest pain
Muscle pain or weakness
Muscle stiffness
Abnormal burning, numbness, or tingling sensations
Breathing difficulties, slow breathing, or shallow breathing
Urination problems, such as:
+ Inability to pass urine
+ Changes in urine frequency or volume
+ Blood in the urine
Swelling in the arms or legs
Difficulty controlling body movements, twitching, or changes in balance
Trouble swallowing or speaking
Uncontrolled eye movements
Abnormal heartbeat
Other Possible Side Effects
Like all medications, this drug can cause side effects. While many people may not experience any side effects or only minor ones, it's essential to discuss any concerns with your doctor. If you experience any of the following side effects or any other unusual symptoms, contact your doctor for advice:
Dizziness, drowsiness, fatigue, or weakness
Sleep disturbances
Upset stomach or vomiting
Headache
Constipation
This is not an exhaustive list of possible side effects. If you have questions or concerns, consult your doctor. You can also report side effects to the FDA at 1-800-332-1088 or online at https://www.fda.gov/medwatch.
Although rare, some people may experience severe and potentially life-threatening side effects while taking this medication. If you notice any of the following symptoms, contact your doctor or seek immediate medical attention:
Signs of an allergic reaction, such as:
+ Rash
+ Hives
+ Itching
+ Red, swollen, blistered, or peeling skin with or without fever
+ Wheezing
+ Tightness in the chest or throat
+ Trouble breathing, swallowing, or talking
+ Unusual hoarseness
+ Swelling of the mouth, face, lips, tongue, or throat
Severe dizziness or fainting
Confusion
New or worsening mental, mood, or behavioral changes
Hallucinations (seeing or hearing things that are not there)
Seizures
Changes in balance or coordination
Changes in vision
Chest pain
Muscle pain or weakness
Muscle stiffness
Abnormal burning, numbness, or tingling sensations
Breathing difficulties, slow breathing, or shallow breathing
Urination problems, such as:
+ Inability to pass urine
+ Changes in urine frequency or volume
+ Blood in the urine
Swelling in the arms or legs
Difficulty controlling body movements, twitching, or changes in balance
Trouble swallowing or speaking
Uncontrolled eye movements
Abnormal heartbeat
Other Possible Side Effects
Like all medications, this drug can cause side effects. While many people may not experience any side effects or only minor ones, it's essential to discuss any concerns with your doctor. If you experience any of the following side effects or any other unusual symptoms, contact your doctor for advice:
Dizziness, drowsiness, fatigue, or weakness
Sleep disturbances
Upset stomach or vomiting
Headache
Constipation
This is not an exhaustive list of possible side effects. If you have questions or concerns, consult your doctor. You can also report side effects to the FDA at 1-800-332-1088 or online at https://www.fda.gov/medwatch.
Seek Immediate Medical Attention If You Experience:
- Severe drowsiness or sedation that interferes with daily activities
- Extreme muscle weakness
- Confusion, hallucinations, or unusual thoughts/behavior
- Seizures
- Difficulty breathing
- Signs of withdrawal (if dose is missed or stopped suddenly): increased spasticity, muscle rigidity, high fever, rapid heart rate, changes in mental status, itching, or tingling sensations.
Before Using This Medicine
Before Taking This Medication: Important Information to Share with Your Doctor
It is essential to inform your doctor about the following:
Any allergies you have, including allergies to this medication, its components, or other substances, such as foods or drugs. Be sure to describe the symptoms you experienced as a result of the allergy.
All medications you are currently taking, including prescription and over-the-counter (OTC) drugs, natural products, and vitamins. This is crucial to avoid potential interactions between this medication and other substances.
* Any existing health problems, as this medication may interact with certain conditions.
To ensure your safety, it is vital to verify that it is safe to take this medication with all your current medications and health conditions. Always consult your doctor before starting, stopping, or changing the dose of any medication.
It is essential to inform your doctor about the following:
Any allergies you have, including allergies to this medication, its components, or other substances, such as foods or drugs. Be sure to describe the symptoms you experienced as a result of the allergy.
All medications you are currently taking, including prescription and over-the-counter (OTC) drugs, natural products, and vitamins. This is crucial to avoid potential interactions between this medication and other substances.
* Any existing health problems, as this medication may interact with certain conditions.
To ensure your safety, it is vital to verify that it is safe to take this medication with all your current medications and health conditions. Always consult your doctor before starting, stopping, or changing the dose of any medication.
Precautions & Cautions
It is essential to inform all your healthcare providers, including doctors, nurses, pharmacists, and dentists, that you are taking this medication.
Before operating a vehicle or engaging in any activity that requires your full attention, wait until you understand how this medication affects you. It is also crucial to discuss the use of alcohol, marijuana, or other forms of cannabis, as well as prescription or over-the-counter (OTC) medications that may cause drowsiness, with your doctor.
Do not abruptly discontinue this medication, as this may increase your risk of experiencing side effects, including hallucinations (perceiving things that are not present), seizures, high fever, muscle stiffness, and confusion. In rare cases, sudden discontinuation can lead to organ damage and even death. If you need to stop taking this medication, your doctor will instruct you on how to gradually taper off the dosage. Be sure to consult your doctor if you experience any new or worsening symptoms.
When administering this medication to children, exercise caution, as they may be at a higher risk of developing certain side effects.
If you are pregnant, planning to become pregnant, or are breastfeeding, inform your doctor. It is necessary to discuss the potential benefits and risks of this medication to both you and your baby. Taking this medication during pregnancy may cause withdrawal symptoms in the newborn.
Before operating a vehicle or engaging in any activity that requires your full attention, wait until you understand how this medication affects you. It is also crucial to discuss the use of alcohol, marijuana, or other forms of cannabis, as well as prescription or over-the-counter (OTC) medications that may cause drowsiness, with your doctor.
Do not abruptly discontinue this medication, as this may increase your risk of experiencing side effects, including hallucinations (perceiving things that are not present), seizures, high fever, muscle stiffness, and confusion. In rare cases, sudden discontinuation can lead to organ damage and even death. If you need to stop taking this medication, your doctor will instruct you on how to gradually taper off the dosage. Be sure to consult your doctor if you experience any new or worsening symptoms.
When administering this medication to children, exercise caution, as they may be at a higher risk of developing certain side effects.
If you are pregnant, planning to become pregnant, or are breastfeeding, inform your doctor. It is necessary to discuss the potential benefits and risks of this medication to both you and your baby. Taking this medication during pregnancy may cause withdrawal symptoms in the newborn.
Overdose Information
Overdose Symptoms:
- Severe drowsiness or coma
- Respiratory depression (slow, shallow breathing)
- Seizures
- Hypotonia (severe muscle weakness)
- Hypothermia
- Bradycardia (slow heart rate)
- Hyporeflexia (decreased reflexes)
What to Do:
Seek immediate medical attention. Call 911 or Poison Control at 1-800-222-1222. Management is supportive, including maintaining airway, breathing, and circulation. There is no specific antidote.
Drug Interactions
Major Interactions
- CNS depressants (e.g., alcohol, opioids, benzodiazepines, tricyclic antidepressants): Increased CNS depression (sedation, respiratory depression).
- Tricyclic antidepressants: May potentiate the muscle relaxant effect of baclofen, leading to increased hypotonia.
- Antihypertensives: May cause additive hypotensive effects.
Moderate Interactions
- Levodopa/Carbidopa: May cause increased dyskinesia, confusion, and hallucinations in patients with Parkinson's disease.
- Monoamine Oxidase Inhibitors (MAOIs): Concurrent use may increase CNS depression and hypotonia (though less common with oral baclofen).
Monitoring
Baseline Monitoring
Assessment of Spasticity
Rationale: To establish baseline severity and type of spasticity (e.g., Ashworth Scale, functional assessment).
Timing: Prior to initiation of therapy
Renal Function (BUN, Creatinine, eGFR)
Rationale: Baclofen is primarily renally excreted; impairment requires dose adjustment.
Timing: Prior to initiation of therapy, especially in elderly or those with risk factors for renal dysfunction
Routine Monitoring
Efficacy (Reduction in Spasticity, Pain, Improved Function)
Frequency: Regularly during titration and periodically thereafter (e.g., monthly initially, then every 3-6 months)
Target: Individualized based on patient goals and functional improvement
Action Threshold: Lack of efficacy or worsening symptoms may require dose adjustment or alternative therapy.
Adverse Effects (Sedation, Dizziness, Weakness, Nausea)
Frequency: Daily during titration, then periodically (e.g., at each follow-up visit)
Target: Minimal to tolerable side effects
Action Threshold: Intolerable side effects require dose reduction or discontinuation.
Renal Function (BUN, Creatinine, eGFR)
Frequency: Periodically, especially in patients with pre-existing renal impairment or those on long-term therapy (e.g., every 6-12 months or as clinically indicated)
Target: Within normal limits or stable for patient's baseline
Action Threshold: Significant decline in renal function requires dose adjustment.
Symptom Monitoring
- Excessive drowsiness or sedation
- Dizziness or lightheadedness
- Muscle weakness
- Nausea or vomiting
- Confusion or disorientation
- Headache
- Insomnia
- Urinary frequency or retention
- Signs of withdrawal (if abruptly stopped): increased spasticity, hallucinations, seizures, hyperthermia, rhabdomyolysis
Special Patient Groups
Pregnancy
Baclofen is Pregnancy Category C. It should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus. Animal studies have shown adverse effects, but there are no adequate and well-controlled studies in pregnant women.
Trimester-Specific Risks:
First Trimester:
Potential for developmental toxicity observed in animal studies at doses higher than human therapeutic range. Human data are limited.
Second Trimester:
Limited human data, generally considered similar risk to first trimester.
Third Trimester:
Potential for neonatal withdrawal symptoms (e.g., seizures, hypertonia, tremor) if exposure occurs close to delivery, especially with chronic use.
Lactation
Baclofen is excreted into breast milk in small amounts. The American Academy of Pediatrics considers it compatible with breastfeeding. Monitor breastfed infants for signs of sedation (e.g., lethargy, poor feeding) or unusual irritability.
Infant Risk:
Low risk. Monitor for sedation, hypotonia, or poor feeding.
Pediatric Use
Use in children is generally off-label for spasticity and requires careful titration due to varying pharmacokinetics and potential for increased sensitivity to side effects. Safety and efficacy are not well-established for all pediatric age groups. Abrupt withdrawal can be particularly dangerous in children.
Geriatric Use
Elderly patients may be more sensitive to the effects of baclofen, particularly CNS side effects (sedation, confusion, dizziness) and muscle weakness. They are also more likely to have impaired renal function, which can lead to drug accumulation. Start with lower doses and titrate slowly, monitoring closely for adverse effects.
Clinical Information
Clinical Pearls
- Always titrate baclofen dose slowly upwards to minimize side effects and optimize therapeutic effect.
- Emphasize the critical importance of *not* abruptly discontinuing baclofen due to severe and potentially life-threatening withdrawal symptoms (e.g., seizures, hallucinations, hyperthermia, rhabdomyolysis).
- Caution patients about additive CNS depression with alcohol and other sedatives.
- Monitor renal function, especially in elderly patients or those with pre-existing kidney disease, as baclofen is primarily renally excreted.
- Baclofen is generally more effective for spasticity of spinal origin (e.g., MS, spinal cord injury) than for cerebral origin (e.g., stroke, cerebral palsy), though it is used for both.
- Consider the impact of muscle weakness on functional mobility, especially in patients who rely on spasticity for postural support.
Alternative Therapies
- Tizanidine (alpha-2 adrenergic agonist)
- Dantrolene (direct muscle relaxant)
- Diazepam (benzodiazepine)
- Botulinum toxin injections (for focal spasticity)
- Physical therapy
- Occupational therapy
Cost & Coverage
Average Cost:
Varies widely, typically $10-$50 per 30 tablets (20mg)
Generic Available:
Yes
Insurance Coverage:
Tier 1 (Generic)
General Drug Facts
If your symptoms or health issues persist or worsen, it's essential to contact your doctor for further guidance. To ensure your safety, never share your medication with others or take someone else's medication. Some medications may come with an additional patient information leaflet, so be sure to check with your pharmacist for more information. If you have any questions or concerns about your medication, don't hesitate to reach out to your doctor, nurse, pharmacist, or other healthcare provider. In the event of a suspected overdose, immediately call your local poison control center or seek medical attention. When seeking help, be prepared to provide details about the medication, including the amount taken and the time it happened, to ensure you receive the best possible care.