Skelaxin 800mg Tablets
It is used to relax muscles.
Drug Class
Skeletal Muscle Relaxant
Pharmacologic Class
Centrally Acting Skeletal Muscle Relaxant
Pregnancy Category
Category C
FDA Approved
Aug 1962
DEA Schedule
Not Controlled
Overview
What is this medicine?
Metaxalone is a muscle relaxant used to treat muscle spasms and pain caused by injuries or other muscle conditions. It works by affecting the brain and nervous system to help relax the muscles.
How to Use This Medicine
Taking Your Medication
To use this medication correctly, follow your doctor's instructions and read all the information provided. You can take this medication with or without food, but be aware that taking it with food may increase sleepiness or dizziness.
Storing and Disposing of Your Medication
Store your medication at room temperature in a dry place, avoiding the bathroom. Keep all medications in a safe location, out of the reach of children and pets. When disposing of unused or expired medication, do not flush it down the toilet or pour it down the drain unless instructed to do so. Instead, consult your pharmacist for guidance on the best disposal method or check if there are drug take-back programs in your area.
Missing a Dose
If you take this medication regularly, take a missed dose as soon as you remember. However, if it's close to the time for your next dose, skip the missed dose and resume your normal schedule. Do not take two doses at the same time or take extra doses. If you take this medication as needed, do not take it more frequently than directed by your doctor.
To use this medication correctly, follow your doctor's instructions and read all the information provided. You can take this medication with or without food, but be aware that taking it with food may increase sleepiness or dizziness.
Storing and Disposing of Your Medication
Store your medication at room temperature in a dry place, avoiding the bathroom. Keep all medications in a safe location, out of the reach of children and pets. When disposing of unused or expired medication, do not flush it down the toilet or pour it down the drain unless instructed to do so. Instead, consult your pharmacist for guidance on the best disposal method or check if there are drug take-back programs in your area.
Missing a Dose
If you take this medication regularly, take a missed dose as soon as you remember. However, if it's close to the time for your next dose, skip the missed dose and resume your normal schedule. Do not take two doses at the same time or take extra doses. If you take this medication as needed, do not take it more frequently than directed by your doctor.
Lifestyle & Tips
- Avoid alcohol and other CNS depressants (e.g., sedatives, tranquilizers) as they can increase drowsiness and dizziness.
- Do not drive or operate heavy machinery until you know how this medication affects you, as it can cause drowsiness and dizziness.
- Take with food if stomach upset occurs, as food can also increase absorption.
- Report any signs of liver problems (e.g., yellowing of skin/eyes, dark urine, unusual tiredness) to your doctor immediately.
Available Forms & Alternatives
Available Strengths:
Generic Alternatives:
Dosing & Administration
Adult Dosing
Standard Dose:
800 mg three to four times a day
Dose Range:
2400 - 3200 mg
Condition-Specific Dosing:
acute_pain:
800 mg three to four times daily for symptomatic relief of acute, painful musculoskeletal conditions.
Pediatric Dosing
Neonatal:
Not established
Infant:
Not established
Child:
Not established (Safety and effectiveness in pediatric patients under 12 years of age have not been established).
Adolescent:
Not established (Safety and effectiveness in pediatric patients under 12 years of age have not been established).
Dose Adjustments
Renal Impairment:
Mild:
No specific dose adjustment provided; use with caution.
Moderate:
No specific dose adjustment provided; use with caution.
Severe:
No specific dose adjustment provided; use with caution.
Dialysis:
Not available; renal excretion of unchanged drug is minor, but metabolites are renally excreted. Use with caution.
Hepatic Impairment:
Mild:
Use with caution; monitor liver function.
Moderate:
Contraindicated in patients with known or suspected impaired hepatic function.
Severe:
Contraindicated in patients with known or suspected impaired hepatic function.
Pharmacology
Mechanism of Action
The mechanism of action of metaxalone has not been precisely identified but may be due to general central nervous system (CNS) depression. It does not directly relax tense skeletal muscles in man. It is thought to produce its effects by acting on the CNS rather than directly on the skeletal muscle.
Pharmacokinetics
Absorption:
Bioavailability:
Not precisely quantified, but well absorbed.
Tmax:
2-4 hours (fasted); 4-5 hours (with high-fat meal)
FoodEffect:
High-fat meal significantly increases Cmax (up to 142%) and AUC (up to 115%) compared to fasted state.
Distribution:
Vd:
Not readily available
ProteinBinding:
Not extensively reported, generally considered low.
CnssPenetration:
Yes
Elimination:
HalfLife:
8-10 hours (range 2.4-21.6 hours)
Clearance:
Not readily available
ExcretionRoute:
Primarily renal (as metabolites)
Unchanged:
< 1% (in urine)
Pharmacodynamics
OnsetOfAction:
Within 1 hour
PeakEffect:
2-4 hours
DurationOfAction:
4-6 hours
Safety & Warnings
Side Effects
Urgent Side Effects: Seek Medical Help Right Away
While rare, some people may experience severe and potentially life-threatening side effects when taking this medication. If you notice any of the following signs or symptoms, contact your doctor or seek medical attention immediately:
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
Fever, chills, or sore throat
Severe stomach pain
Dark urine or yellow skin or eyes
Serotonin syndrome, a rare but life-threatening condition, which may occur with high doses of this medication or when taken with certain other drugs, such as those for depression, migraines, or other conditions. Symptoms may include:
+ Agitation
+ Change in balance
+ Confusion
+ Hallucinations
+ Fever
+ Fast or abnormal heartbeat
+ Flushing
+ Muscle twitching or stiffness
+ Seizures
+ Shivering or shaking
+ Excessive sweating
+ Severe diarrhea
+ Upset stomach or vomiting
+ Severe headache
Other Possible Side Effects
Most people taking this medication will not experience side effects or will only have mild ones. However, if you notice any of the following side effects, contact your doctor or seek medical attention if they bother you or do not go away:
Dizziness or drowsiness
Headache
Feeling nervous or excitable
Irritability
Upset stomach or vomiting
Reporting Side Effects
This is not a comprehensive list of all possible side effects. If you have questions or concerns about side effects, contact your doctor. You can also report side effects to the FDA at 1-800-332-1088 or online at https://www.fda.gov/medwatch.
While rare, some people may experience severe and potentially life-threatening side effects when taking this medication. If you notice any of the following signs or symptoms, contact your doctor or seek medical attention immediately:
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
Fever, chills, or sore throat
Severe stomach pain
Dark urine or yellow skin or eyes
Serotonin syndrome, a rare but life-threatening condition, which may occur with high doses of this medication or when taken with certain other drugs, such as those for depression, migraines, or other conditions. Symptoms may include:
+ Agitation
+ Change in balance
+ Confusion
+ Hallucinations
+ Fever
+ Fast or abnormal heartbeat
+ Flushing
+ Muscle twitching or stiffness
+ Seizures
+ Shivering or shaking
+ Excessive sweating
+ Severe diarrhea
+ Upset stomach or vomiting
+ Severe headache
Other Possible Side Effects
Most people taking this medication will not experience side effects or will only have mild ones. However, if you notice any of the following side effects, contact your doctor or seek medical attention if they bother you or do not go away:
Dizziness or drowsiness
Headache
Feeling nervous or excitable
Irritability
Upset stomach or vomiting
Reporting Side Effects
This is not a comprehensive list of all possible side effects. If you have questions or concerns about side effects, contact 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 dizziness
- Difficulty breathing
- Yellowing of the skin or eyes (jaundice)
- Dark urine
- Unusual bleeding or bruising
- Severe allergic reaction (rash, itching, swelling, severe dizziness, trouble breathing)
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.
If you have a history of kidney disease or liver disease.
* If you have anemia or have been informed that you are at risk of developing anemia.
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 adjust 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, its components, or other substances, such as foods or drugs. Be sure to describe the symptoms you experienced.
If you have a history of kidney disease or liver disease.
* If you have anemia or have been informed that you are at risk of developing anemia.
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 adjust 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. Adhere strictly to the dosage prescribed by your doctor, as taking more than the recommended amount can increase your risk of experiencing severe side effects.
Until you understand how this medication affects you, avoid operating a vehicle or engaging in any activities that require your full attention. Before consuming alcohol, using marijuana or other cannabis products, or taking any prescription or over-the-counter medications that may impair your reactions, consult with your doctor.
This medication is typically used in conjunction with rest, physical therapy, pain management medications, and other therapeutic interventions. Be aware that it may influence the results of certain laboratory tests, so it is crucial that your doctor and laboratory personnel are informed of your use of this drug.
If you are 65 years of age or older, exercise caution when using this medication, as you may be more susceptible to side effects. If you are pregnant, planning to become pregnant, or are breastfeeding, discuss the potential benefits and risks of this medication with your doctor to make an informed decision regarding its use.
Until you understand how this medication affects you, avoid operating a vehicle or engaging in any activities that require your full attention. Before consuming alcohol, using marijuana or other cannabis products, or taking any prescription or over-the-counter medications that may impair your reactions, consult with your doctor.
This medication is typically used in conjunction with rest, physical therapy, pain management medications, and other therapeutic interventions. Be aware that it may influence the results of certain laboratory tests, so it is crucial that your doctor and laboratory personnel are informed of your use of this drug.
If you are 65 years of age or older, exercise caution when using this medication, as you may be more susceptible to side effects. If you are pregnant, planning to become pregnant, or are breastfeeding, discuss the potential benefits and risks of this medication with your doctor to make an informed decision regarding its use.
Overdose Information
Overdose Symptoms:
- Nausea
- Vomiting
- Drowsiness
- Dizziness
- Ataxia (loss of coordination)
- Hypotension (low blood pressure)
- Respiratory depression
- Coma
What to Do:
Seek immediate medical attention. Call 911 or Poison Control at 1-800-222-1222. Treatment is generally supportive, including gastric lavage, activated charcoal, and maintenance of vital signs.
Drug Interactions
Major Interactions
Moderate Interactions
- CYP1A2 inhibitors (e.g., cimetidine, fluvoxamine, ciprofloxacin) - potential for increased metaxalone levels
- CYP2D6 inhibitors (e.g., fluoxetine, paroxetine, quinidine) - potential for increased metaxalone levels
- CYP1A2 inducers (e.g., rifampin, omeprazole) - potential for decreased metaxalone levels
- CYP2D6 inducers (e.g., dexamethasone, rifampin) - potential for decreased metaxalone levels
Monitoring
Baseline Monitoring
Liver Function Tests (LFTs)
Rationale: Metaxalone is extensively metabolized by the liver and is contraindicated in patients with impaired hepatic function. Baseline assessment is crucial.
Timing: Prior to initiation of therapy
Renal Function (BUN, Creatinine)
Rationale: Although renal excretion of unchanged drug is minor, metabolites are renally excreted. Caution is advised in renal impairment.
Timing: Prior to initiation of therapy, especially in patients with known renal issues
Routine Monitoring
Liver Function Tests (LFTs)
Frequency: Periodically, especially with prolonged use or if symptoms of hepatic dysfunction develop.
Target: Within normal limits
Action Threshold: Significant elevation (e.g., >3x ULN) or signs/symptoms of liver injury; consider discontinuation.
Signs/Symptoms of CNS Depression
Frequency: Regularly throughout therapy
Target: Minimal to no excessive sedation, dizziness, or impaired coordination
Action Threshold: Excessive drowsiness, dizziness, confusion, or impaired motor skills; consider dose reduction or discontinuation.
Symptom Monitoring
- Drowsiness
- Dizziness
- Nausea
- Vomiting
- Stomach upset
- Headache
- Nervousness
- Irritability
- Jaundice (yellowing of skin/eyes)
- Dark urine
- Unusual fatigue (signs of liver dysfunction)
Special Patient Groups
Pregnancy
Category C. Animal reproduction studies have shown an adverse effect on the fetus and there are no adequate and well-controlled studies in humans, but potential benefits may warrant use of the drug in pregnant women despite potential risks.
Trimester-Specific Risks:
First Trimester:
Potential for fetal harm based on animal data; use only if clearly needed.
Second Trimester:
Potential for fetal harm based on animal data; use only if clearly needed.
Third Trimester:
Potential for fetal harm based on animal data; use only if clearly needed.
Lactation
It is not known whether metaxalone is excreted in human milk. Because many drugs are excreted in human milk, caution should be exercised when metaxalone is administered to a nursing woman. Consider risks vs. benefits; monitor infant for sedation.
Infant Risk:
Low to Moderate (L3). Potential for sedation in the infant. Monitor for drowsiness, poor feeding, or developmental delay.
Pediatric Use
Safety and effectiveness in pediatric patients under 12 years of age have not been established. Not recommended for this age group.
Geriatric Use
Use with caution in elderly patients due to increased susceptibility to CNS adverse effects (e.g., dizziness, sedation, falls). Start with lower doses and titrate slowly. Monitor for cognitive impairment and falls.
Clinical Information
Clinical Pearls
- Metaxalone is often considered to have a lower potential for sedation and abuse compared to some other muscle relaxants (e.g., carisoprodol), but sedation can still occur.
- Taking metaxalone with food can significantly increase its absorption and may help reduce gastrointestinal upset.
- Patients should be advised to avoid activities requiring mental alertness until they know how the drug affects them.
- Liver function should be monitored, especially in patients with pre-existing hepatic impairment or during prolonged therapy.
Alternative Therapies
- Cyclobenzaprine (Flexeril)
- Tizanidine (Zanaflex)
- Baclofen (Lioresal)
- Methocarbamol (Robaxin)
- Carisoprodol (Soma) - higher abuse potential
- Orphenadrine (Norflex)
- Non-pharmacological treatments: physical therapy, heat/cold therapy, rest, exercise.
Cost & Coverage
Average Cost:
Varies widely, typically $10-$50 for generic 800mg, $100-$300+ for brand Skelaxin per 30 tablets
Generic Available:
Yes
Insurance Coverage:
Tier 1 or 2 (generic), Tier 3 or 4 (brand)
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 this 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 emergency medical attention. When seeking help, be prepared to provide details about the medication, including the amount taken and the time it happened, to help healthcare professionals provide the best possible care.