Baclofen 50mcg/ml Pf Syr, 1ml
WARNING: Unsafe side effects have happened when this drug was stopped all of a sudden. Some of these side effects have been high fever, mental changes, more spasms, and muscle stiffness. Rarely, these side effects have led to very bad muscle problems, organ problems, and death. Avoid stopping this drug all of a sudden without talking with your doctor. Be sure you get your pump refilled on time and you know about the pump alarms and what to do if the pump alarm goes off. Tell your doctor if you have ever had signs of withdrawal while getting baclofen tablets or shot. Call your doctor right away if you have signs of withdrawal.Read the package insert for more details. @ COMMON USES: 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
Pharmacologic Class
Centrally acting muscle relaxant; GABA-B receptor agonist
Pregnancy Category
Category C
FDA Approved
Mar 1992
DEA Schedule
Not Controlled
Overview
What is this medicine?
Baclofen intrathecal injection is a medicine delivered directly into the fluid around your spinal cord using a special pump. It helps to relax very stiff muscles (spasticity) that are caused by conditions like multiple sclerosis, spinal cord injury, or cerebral palsy, when other medicines haven't worked.
How to Use This Medicine
To use this medication correctly, follow your doctor's instructions and carefully read all accompanying information. Adhere to the dosage and administration guidelines provided. This medication is administered via injection into the spine.
For storage and disposal, consult with your doctor, nurse, or pharmacist to determine the best approach if you need to keep this medication at home.
If you miss a dose, contact your doctor promptly to receive guidance on the next steps to take.
For storage and disposal, consult with your doctor, nurse, or pharmacist to determine the best approach if you need to keep this medication at home.
If you miss a dose, contact your doctor promptly to receive guidance on the next steps to take.
Lifestyle & Tips
- Always keep your scheduled pump refill appointments to prevent the pump from running out of medicine.
- Carry an identification card stating you have an intrathecal pump and are receiving baclofen.
- Be aware of the signs of baclofen withdrawal (sudden increase in muscle stiffness, itching, fever, confusion, seizures) and overdose (extreme drowsiness, severe muscle weakness, difficulty breathing).
- Avoid abrupt discontinuation of therapy, as this can be life-threatening.
- Do not consume alcohol or other CNS depressants without consulting 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:
Highly individualized, administered via intrathecal pump. Initial screening dose via lumbar puncture (50 mcg, then 75 mcg, then 100 mcg at 24-hour intervals). Initial pump dose is 2-4 times the effective screening dose over 24 hours. Maintenance dose typically 300-800 mcg/day.
Dose Range:
12 - 2000 mg
Condition-Specific Dosing:
spasticityOfSpinalOrigin:
Initial screening dose 50 mcg, then 75 mcg, then 100 mcg. Initial pump dose 2-4 times effective screening dose. Maintenance 300-800 mcg/day (range 12-2000 mcg/day).
spasticityOfCerebralOrigin:
Initial screening dose 25 mcg, then 50 mcg, then 75 mcg, then 100 mcg. Initial pump dose 1.5-2 times effective screening dose. Maintenance 90-700 mcg/day (average 200-300 mcg/day).
Pediatric Dosing
Neonatal:
Not established
Infant:
Not established
Child:
Highly individualized. Screening dose 25-50 mcg. Initial pump dose 1.5-2 times effective screening dose over 24 hours. Maintenance dose 25-1200 mcg/day (average 200-400 mcg/day).
Adolescent:
Highly individualized. Screening dose 25-50 mcg. Initial pump dose 1.5-2 times effective screening dose over 24 hours. Maintenance dose 25-1200 mcg/day (average 200-400 mcg/day).
Dose Adjustments
Renal Impairment:
Mild:
No specific adjustment for intrathecal route due to minimal systemic exposure, but monitor for systemic effects if any.
Moderate:
No specific adjustment for intrathecal route due to minimal systemic exposure, but monitor for systemic effects if any.
Severe:
No specific adjustment for intrathecal route due to minimal systemic exposure, but monitor for systemic effects if any.
Dialysis:
Not applicable for intrathecal route as systemic exposure is minimal.
Hepatic Impairment:
Mild:
No specific adjustment for intrathecal route due to minimal systemic exposure.
Moderate:
No specific adjustment for intrathecal route due to minimal systemic exposure.
Severe:
No specific adjustment for intrathecal route due to minimal systemic exposure.
Pharmacology
Mechanism of Action
Baclofen is a gamma-aminobutyric acid (GABA) derivative that acts as a GABA-B receptor agonist. It is thought to inhibit both monosynaptic and polysynaptic reflexes at the spinal cord level, possibly by hyperpolarization of afferent terminals and by presynaptic inhibition of excitatory neurotransmitter release. This action reduces spasticity, muscle clonus, and associated pain.
Pharmacokinetics
Absorption:
Bioavailability:
Not applicable (directly administered to CSF)
Tmax:
CSF: 0.5-1 hour (after bolus)
FoodEffect:
Not applicable (intrathecal)
Distribution:
Vd:
CSF: Approximately 22-33 mL (limited systemic distribution)
ProteinBinding:
Approximately 30%
CnssPenetration:
Yes (direct administration)
Elimination:
HalfLife:
CSF: 1.5-5 hours; Systemic: 2.5-4 hours
Clearance:
Not readily quantifiable for intrathecal CSF clearance; Systemic: Approximately 180 mL/min
ExcretionRoute:
Primarily renal (70-80% unchanged in urine) after systemic absorption from CSF
Unchanged:
70-80% (systemic)
Pharmacodynamics
OnsetOfAction:
0.5-1 hour (intrathecal)
PeakEffect:
3-4 hours (intrathecal)
DurationOfAction:
4-8 hours (single bolus); up to 24 hours (continuous infusion)
Safety & Warnings
BLACK BOX WARNING
Abrupt discontinuation of intrathecal baclofen, regardless of the cause, has resulted in severe withdrawal symptoms that include high fever, altered mental status, exaggerated spasticity, and muscle rigidity, which in rare cases has advanced to rhabdomyolysis, multi-organ system failure, and death. Prevention of abrupt discontinuation of intrathecal baclofen is important. Refill appointments should be scheduled regularly to prevent depletion of the pump reservoir. Patients and caregivers should be instructed on the importance of keeping refill appointments and on the early symptoms of baclofen withdrawal.
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
Vision changes
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. Many people may not experience any side effects or may only have mild ones. If you are bothered by any of the following side effects or if they persist, contact your doctor:
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 about side effects, 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
Vision changes
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. Many people may not experience any side effects or may only have mild ones. If you are bothered by any of the following side effects or if they persist, contact your doctor:
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 about side effects, 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:
- Sudden increase in muscle stiffness or spasms
- Itching or skin rash
- High fever
- Confusion or hallucinations
- Seizures
- Extreme drowsiness or sedation
- Severe muscle weakness (floppy muscles)
- Difficulty breathing or slow breathing
- Lightheadedness or dizziness
- Nausea or vomiting
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, any of its components, or other substances, such as foods or drugs. Be sure to describe the allergic reaction you experienced, including any symptoms that occurred.
If you currently have an infection.
This list is not exhaustive, and it is crucial to discuss all your medications (including prescription, over-the-counter, natural products, and vitamins) and health conditions with your doctor and pharmacist. They will help determine if it is safe to take this medication in conjunction with your other medications and health issues.
Remember, do not start, stop, or modify the dosage of any medication without first consulting your doctor to ensure your safety.
It is essential to inform your doctor about the following:
Any allergies you have, including allergies to this medication, any of its components, or other substances, such as foods or drugs. Be sure to describe the allergic reaction you experienced, including any symptoms that occurred.
If you currently have an infection.
This list is not exhaustive, and it is crucial to discuss all your medications (including prescription, over-the-counter, natural products, and vitamins) and health conditions with your doctor and pharmacist. They will help determine if it is safe to take this medication in conjunction with your other medications and health issues.
Remember, do not start, stop, or modify the dosage of any medication without first consulting your doctor to ensure your safety.
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 beforehand.
When administering this medication to a child, exercise caution, as the risk of certain side effects may be increased in pediatric patients.
If you are pregnant, planning to become pregnant, or are breastfeeding, consult your doctor to weigh the benefits and risks of this medication to both you and your baby. Using this drug during pregnancy may lead to withdrawal symptoms in the newborn.
For patients receiving this medication via injection, consult your doctor if you notice a decrease in the drug's effectiveness. Do not exceed the prescribed dosage.
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 beforehand.
When administering this medication to a child, exercise caution, as the risk of certain side effects may be increased in pediatric patients.
If you are pregnant, planning to become pregnant, or are breastfeeding, consult your doctor to weigh the benefits and risks of this medication to both you and your baby. Using this drug during pregnancy may lead to withdrawal symptoms in the newborn.
For patients receiving this medication via injection, consult your doctor if you notice a decrease in the drug's effectiveness. Do not exceed the prescribed dosage.
Overdose Information
Overdose Symptoms:
- Severe hypotonia (flaccid muscles)
- Somnolence progressing to coma
- Respiratory depression or apnea
- Bradycardia
- Hypothermia
- Seizures (especially in children)
- Hyporeflexia
What to Do:
Seek immediate emergency medical attention. Call 911 or Poison Control (1-800-222-1222). Management includes supportive care, maintaining respiration, and potentially withdrawing CSF to reduce baclofen concentration.
Drug Interactions
Major Interactions
Moderate Interactions
- Other muscle relaxants: May increase muscle weakness or hypotonia.
- Lithium: May exacerbate hyperkinetic movements.
Monitoring
Baseline Monitoring
Neurological examination
Rationale: To assess baseline spasticity, muscle tone, reflexes, and motor function.
Timing: Prior to screening dose and pump implantation.
Spasticity assessment (e.g., Ashworth Scale)
Rationale: To quantify baseline spasticity severity and guide initial dosing.
Timing: Prior to screening dose.
Psychological evaluation
Rationale: To assess patient suitability for pump therapy and ability to manage device.
Timing: Prior to pump implantation.
Routine Monitoring
Spasticity assessment
Frequency: Daily during titration, then periodically (e.g., monthly to quarterly) or as needed.
Target: Optimal reduction in spasticity without excessive hypotonia.
Action Threshold: Significant increase in spasticity (consider dose adjustment or pump malfunction); excessive hypotonia (consider dose reduction).
Adverse effects (e.g., sedation, hypotonia, nausea, vomiting, headache, dizziness, seizures)
Frequency: Daily during titration, then at each refill visit and as needed.
Target: Absence or minimal severity of adverse effects.
Action Threshold: Presence of severe or intolerable adverse effects (consider dose adjustment or investigation for overdose).
Pump reservoir volume and function
Frequency: At each refill visit (typically every 1-3 months), and patient/caregiver should monitor alarms.
Target: Adequate drug volume for continuous delivery.
Action Threshold: Low reservoir alarm, pump malfunction alarm, or unexpected rapid depletion (requires immediate attention).
Neurological status (e.g., reflexes, muscle tone, mental status)
Frequency: At each refill visit and as needed.
Target: Stable neurological status.
Action Threshold: Changes suggestive of overdose, withdrawal, or neurological complications.
Symptom Monitoring
- Increased spasticity
- Pruritus
- Hyperthermia
- Altered mental status (confusion, hallucinations)
- Seizures
- Rhabdomyolysis
- Hypotonia
- Somnolence
- Respiratory depression
- Coma
- Cardiovascular instability
Special Patient Groups
Pregnancy
Category C. Use only if the potential benefit justifies the potential risk to the fetus. While systemic exposure is low with intrathecal administration, animal studies have shown adverse effects at high doses. Data in pregnant women are limited.
Trimester-Specific Risks:
First Trimester:
Limited data; theoretical risk of teratogenicity based on animal studies at high systemic doses.
Second Trimester:
Limited data; monitor for fetal well-being.
Third Trimester:
Limited data; monitor for fetal well-being and potential neonatal withdrawal if systemic exposure occurs.
Lactation
L3 (Moderately Safe). Baclofen is excreted in breast milk. Due to the low systemic absorption with intrathecal administration, the amount transferred to breast milk is expected to be minimal. Monitor breastfed infant for sedation or hypotonia.
Infant Risk:
Low risk; monitor for drowsiness, poor feeding, or hypotonia.
Pediatric Use
Approved for severe spasticity of cerebral or spinal origin in children aged 4 years and older. Dosing is highly individualized and requires careful titration. Younger children may be more sensitive to adverse effects. Surgical considerations for pump placement may differ.
Geriatric Use
No specific dose adjustments based on age alone, but elderly patients may be more sensitive to the effects of baclofen and may require lower doses or slower titration. Monitor closely for adverse effects, especially CNS depression and hypotonia.
Clinical Information
Clinical Pearls
- Intrathecal baclofen is indicated for severe spasticity that is unresponsive to oral baclofen or other oral antispastic agents, or for patients who experience intolerable side effects at effective oral doses.
- Therapy requires a surgically implanted pump and catheter for continuous delivery into the intrathecal space.
- A successful screening test (intrathecal bolus) is crucial before pump implantation.
- Dosing is highly individualized and requires careful, slow titration to achieve optimal spasticity control with minimal side effects.
- Abrupt discontinuation of intrathecal baclofen can lead to a life-threatening withdrawal syndrome; patients and caregivers must be educated on this risk and the importance of regular pump refills.
- Patients should carry an identification card indicating they have an intrathecal pump and are on baclofen therapy.
- Monitor for signs of both overdose (excessive hypotonia, sedation, respiratory depression) and withdrawal (increased spasticity, fever, altered mental status, seizures).
Alternative Therapies
- Oral muscle relaxants (e.g., tizanidine, dantrolene, diazepam)
- Botulinum toxin injections (for focal spasticity)
- Physical therapy and occupational therapy
- Surgical interventions (e.g., selective dorsal rhizotomy, orthopedic procedures)
- Other antispasticity agents (e.g., gabapentin, clonidine)
Cost & Coverage
Average Cost:
Highly variable per vial/refill
Generic Available:
Yes
Insurance Coverage:
Specialty Tier / Medical Benefit (often covered under durable medical equipment and pharmacy benefit for drug)
General Drug Facts
If your symptoms or health issues persist or worsen, it is essential to contact your doctor promptly. To ensure safe and effective treatment, never share your medication with others or take someone else's medication. Some medications may come with an additional patient information leaflet, so it's a good idea to check with your pharmacist for more information. If you have any questions or concerns about this medication, don't hesitate to discuss them with your doctor, nurse, pharmacist, or other healthcare provider. In the event of a suspected overdose, immediately call your local poison control center or seek emergency medical attention. When seeking help, be prepared to provide details about the overdose, including the medication taken, the amount, and the time it occurred.