Tizanidine 6mg Capsules
It is used to relax muscles.It may be given to you for other reasons. Talk with the doctor.
Drug Class
Skeletal Muscle Relaxant
Pharmacologic Class
Alpha-2 Adrenergic Agonist
Pregnancy Category
Category C
FDA Approved
Dec 1996
DEA Schedule
Not Controlled
Overview
What is this medicine?
Tizanidine is a medication used to relax muscles and relieve muscle spasms caused by conditions like multiple sclerosis or spinal cord injury. It works by acting on the brain and spinal cord to reduce muscle stiffness and tightness.
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 with or without food, but be consistent in how you take it each time. If you take it with food, always take it with food. If you take it on an empty stomach, always take it on an empty stomach.
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. Dispose of unused or expired medications properly. Do not flush them down the toilet or pour them down the drain unless instructed to do so. If you have questions about disposing of your medication, consult your pharmacist. You may also have access to drug take-back programs in your area.
Missing a Dose
If you take this medication regularly and miss a dose, take it 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. Take your medication with or without food, but be consistent in how you take it each time. If you take it with food, always take it with food. If you take it on an empty stomach, always take it on an empty stomach.
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. Dispose of unused or expired medications properly. Do not flush them down the toilet or pour them down the drain unless instructed to do so. If you have questions about disposing of your medication, consult your pharmacist. You may also have access to drug take-back programs in your area.
Missing a Dose
If you take this medication regularly and miss a dose, take it 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 sedating medications, as they can increase drowsiness and dizziness.
- Be cautious when driving or operating machinery until you know how this medication affects you.
- Take the medication consistently with or without food, but do not switch between taking it with food and without food, as this can change how much medicine your body absorbs.
- Do not stop taking tizanidine suddenly, as this can lead to withdrawal symptoms like high blood pressure, fast heart rate, and increased spasticity. Your doctor will guide you on how to slowly reduce the dose if needed.
Available Forms & Alternatives
Dosing & Administration
Adult Dosing
Standard Dose:
Initial 2 mg orally once daily, titrated gradually. Usual therapeutic dose is 2 mg to 4 mg three times daily. Max 36 mg/day.
Dose Range:
2 - 36 mg
Condition-Specific Dosing:
spasticity:
Initial 2 mg orally once daily, increased by 2 mg to 4 mg at 1 to 4 day intervals until satisfactory reduction of tone is achieved. Doses should be divided into 3 daily doses. Max single dose 16 mg. Max total daily dose 36 mg.
Pediatric Dosing
Neonatal:
Not established
Infant:
Not established
Child:
Not established
Adolescent:
Not established
Dose Adjustments
Renal Impairment:
Mild:
No specific adjustment for mild impairment (CrCl > 50 mL/min).
Moderate:
For CrCl < 25 mL/min, reduce initial dose to 2 mg once daily and titrate slowly based on response and tolerability.
Severe:
For CrCl < 25 mL/min, reduce initial dose to 2 mg once daily and titrate slowly based on response and tolerability.
Dialysis:
Tizanidine is poorly dialyzable. Use with caution and reduce dose for CrCl < 25 mL/min.
Hepatic Impairment:
Mild:
Use with caution. Monitor liver function tests.
Moderate:
Use with caution. Monitor liver function tests. Consider dose reduction.
Severe:
Contraindicated in patients with significant hepatic impairment (e.g., cirrhosis).
Pharmacology
Mechanism of Action
Tizanidine is an alpha-2 adrenergic agonist. It reduces spasticity by increasing presynaptic inhibition of motor neurons at the spinal cord level. Its action is thought to be due to an agonistic effect at central alpha-2 adrenergic receptors, which results in reduced release of excitatory amino acids (e.g., glutamate, aspartate) and inhibition of polysynaptic reflexes.
Pharmacokinetics
Absorption:
Bioavailability:
Approximately 40%
Tmax:
1-2 hours
FoodEffect:
Food increases Cmax by approximately 30% and AUC by 20%, and prolongs Tmax by 25 minutes. This can lead to increased side effects. Administer consistently with or without food.
Distribution:
Vd:
2.4 L/kg
ProteinBinding:
Approximately 30%
CnssPenetration:
Yes
Elimination:
HalfLife:
Approximately 2.5 hours
Clearance:
Not available
ExcretionRoute:
Renal (approximately 60% of dose), Fecal (approximately 20% of dose)
Unchanged:
Approximately 5% (renal)
Pharmacodynamics
OnsetOfAction:
Within 1 hour
PeakEffect:
1-2 hours
DurationOfAction:
3-6 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 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
Signs of liver problems, including:
+ Dark urine
+ Tiredness
+ Decreased appetite
+ Upset stomach or stomach pain
+ Light-colored stools
+ Vomiting
+ Yellow skin or eyes
Signs of a urinary tract infection (UTI), such as:
+ Blood in the urine
+ Burning or pain when passing urine
+ Frequent or urgent need to urinate
+ Fever
+ Lower stomach pain
+ Pelvic pain
Severe dizziness or fainting
Confusion
Hallucinations (seeing or hearing things that are not there)
Mood changes
Changes in behavior
Slow heartbeat
Fever, chills, or sore throat
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 notice any of the following side effects or any other symptoms that concern you or do not go away, contact your doctor or seek medical attention:
Dry mouth
Dizziness
Drowsiness
Fatigue
* Weakness
Reporting Side Effects
This is not an exhaustive list of 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 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
Signs of liver problems, including:
+ Dark urine
+ Tiredness
+ Decreased appetite
+ Upset stomach or stomach pain
+ Light-colored stools
+ Vomiting
+ Yellow skin or eyes
Signs of a urinary tract infection (UTI), such as:
+ Blood in the urine
+ Burning or pain when passing urine
+ Frequent or urgent need to urinate
+ Fever
+ Lower stomach pain
+ Pelvic pain
Severe dizziness or fainting
Confusion
Hallucinations (seeing or hearing things that are not there)
Mood changes
Changes in behavior
Slow heartbeat
Fever, chills, or sore throat
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 notice any of the following side effects or any other symptoms that concern you or do not go away, contact your doctor or seek medical attention:
Dry mouth
Dizziness
Drowsiness
Fatigue
* Weakness
Reporting Side Effects
This is not an exhaustive list of 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 dizziness or fainting (signs of low blood pressure)
- Very slow heart rate
- Yellowing of the skin or eyes, dark urine, nausea, vomiting, or stomach pain (signs of liver problems)
- Hallucinations or unusual thoughts/behaviors
- Difficulty breathing or swallowing
- Rash or severe allergic reaction
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 allergic reaction you experienced, including the symptoms that occurred.
If you are currently taking ciprofloxacin or fluvoxamine, as these medications may interact with this drug.
Please note that this is not an exhaustive list of all potential interactions. To ensure your safety, it is crucial to disclose all of your medications, including:
Prescription and over-the-counter (OTC) drugs
Natural products
* Vitamins
Additionally, inform your doctor about any existing health problems. It is vital to verify that it is safe to take this medication in conjunction with your other medications and health conditions.
Remember, do not start, stop, or modify the dosage of any medication without first consulting your doctor. This will help prevent potential interactions and ensure your safety while taking this 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 allergic reaction you experienced, including the symptoms that occurred.
If you are currently taking ciprofloxacin or fluvoxamine, as these medications may interact with this drug.
Please note that this is not an exhaustive list of all potential interactions. To ensure your safety, it is crucial to disclose all of your medications, including:
Prescription and over-the-counter (OTC) drugs
Natural products
* Vitamins
Additionally, inform your doctor about any existing health problems. It is vital to verify that it is safe to take this medication in conjunction with your other medications and health conditions.
Remember, do not start, stop, or modify the dosage of any medication without first consulting your doctor. This will help prevent potential interactions and ensure your safety while taking this medication.
Precautions & Cautions
It is essential to inform all your healthcare providers, including doctors, nurses, pharmacists, and dentists, that you are taking this medication.
To ensure your safety, avoid driving and other activities that require alertness until you understand how this medication affects you. When getting up from a sitting or lying down position, rise slowly to minimize the risk of dizziness or fainting. Be cautious when navigating stairs.
Before consuming alcohol, marijuana, or other forms of cannabis, or taking prescription or over-the-counter medications that may impair your reactions, consult with your doctor.
If you have been taking a high dose of this medication or using it regularly, do not stop taking it abruptly without first discussing it with your doctor. Stopping the medication suddenly may increase your risk of side effects. If you need to discontinue use, your doctor will guide you on how to gradually stop taking it.
Follow your doctor's instructions for regular blood tests to monitor your condition.
Do not switch between the capsule and tablet forms of this medication without consulting your doctor. If your doctor changes your medication form (e.g., from capsules to tablets), the new form may interact differently with food. Your doctor may monitor you closely after switching to the new form to check for any differences in how it works or potential side effects.
Animal studies have shown that this medication can cause fertility problems. Although it is unclear if this medication affects human fertility, discuss any concerns with your doctor.
If you are 65 years or older, use this medication with caution, as you may be more susceptible to side effects.
If you are pregnant, plan to become pregnant, or are breastfeeding, inform your doctor. You and your doctor will need to discuss the potential benefits and risks of this medication to you and your baby.
To ensure your safety, avoid driving and other activities that require alertness until you understand how this medication affects you. When getting up from a sitting or lying down position, rise slowly to minimize the risk of dizziness or fainting. Be cautious when navigating stairs.
Before consuming alcohol, marijuana, or other forms of cannabis, or taking prescription or over-the-counter medications that may impair your reactions, consult with your doctor.
If you have been taking a high dose of this medication or using it regularly, do not stop taking it abruptly without first discussing it with your doctor. Stopping the medication suddenly may increase your risk of side effects. If you need to discontinue use, your doctor will guide you on how to gradually stop taking it.
Follow your doctor's instructions for regular blood tests to monitor your condition.
Do not switch between the capsule and tablet forms of this medication without consulting your doctor. If your doctor changes your medication form (e.g., from capsules to tablets), the new form may interact differently with food. Your doctor may monitor you closely after switching to the new form to check for any differences in how it works or potential side effects.
Animal studies have shown that this medication can cause fertility problems. Although it is unclear if this medication affects human fertility, discuss any concerns with your doctor.
If you are 65 years or older, use this medication with caution, as you may be more susceptible to side effects.
If you are pregnant, plan to become pregnant, or are breastfeeding, inform your doctor. You and your doctor will need to discuss the potential benefits and risks of this medication to you and your baby.
Overdose Information
Overdose Symptoms:
- Drowsiness
- Dizziness
- Lightheadedness
- Bradycardia (slow heart rate)
- Hypotension (low blood pressure)
- Respiratory depression (slow, shallow breathing)
- Coma
What to Do:
Seek immediate medical attention. Call 911 or Poison Control at 1-800-222-1222. Treatment is supportive, including gastric lavage, activated charcoal, and maintaining vital signs.
Drug Interactions
Contraindicated Interactions
- Fluvoxamine
- Ciprofloxacin
Major Interactions
Moderate Interactions
- Oral contraceptives (moderate CYP1A2 inhibitors)
- Alpha-adrenergic agonists (e.g., clonidine)
- QT-prolonging drugs
Minor Interactions
- Not available
Monitoring
Baseline Monitoring
Liver function tests (ALT, AST)
Rationale: To establish baseline and identify pre-existing hepatic impairment, as tizanidine can cause hepatotoxicity.
Timing: Before initiating therapy
Blood pressure
Rationale: To establish baseline and monitor for hypotension, a common side effect.
Timing: Before initiating therapy
Renal function (CrCl)
Rationale: To assess need for dose adjustment in renal impairment.
Timing: Before initiating therapy
Routine Monitoring
Liver function tests (ALT, AST)
Frequency: At 1, 3, and 6 months after initiation, and periodically thereafter, or if symptoms of liver injury occur.
Target: Within normal limits
Action Threshold: Discontinue if ALT or AST are persistently >3 times the upper limit of normal (ULN) or if symptoms of liver injury occur.
Blood pressure
Frequency: Periodically, especially during dose titration and if symptoms of hypotension occur.
Target: Maintain within patient's normal range, avoid symptomatic hypotension.
Action Threshold: If symptomatic hypotension occurs, reduce dose or discontinue.
Heart rate
Frequency: Periodically, especially during dose titration.
Target: Within normal limits, avoid symptomatic bradycardia.
Action Threshold: If symptomatic bradycardia occurs, reduce dose or discontinue.
Effectiveness (spasticity reduction)
Frequency: Regularly during titration and maintenance.
Target: Improved muscle tone, reduced spasms, improved function.
Action Threshold: Adjust dose based on therapeutic response and tolerability.
Symptom Monitoring
- Dizziness
- Drowsiness
- Dry mouth
- Asthenia (weakness)
- Hypotension (lightheadedness, fainting)
- Bradycardia (slow heart rate)
- Hepatotoxicity (nausea, vomiting, dark urine, yellowing of skin/eyes, abdominal pain)
- Hallucinations
- Psychosis
- Rebound hypertension/tachycardia (upon abrupt discontinuation)
Special Patient Groups
Pregnancy
Category C. Use only if the potential benefit justifies the potential risk to the fetus. Animal studies show adverse effects, but there are no adequate and well-controlled studies in pregnant women.
Trimester-Specific Risks:
First Trimester:
Potential for developmental toxicity based on animal data.
Second Trimester:
Limited human data, animal data suggest potential risk.
Third Trimester:
Limited human data, animal data suggest potential risk. Risk of neonatal withdrawal is unknown.
Lactation
Tizanidine is excreted in human milk. Due to the potential for serious adverse reactions in breastfed infants, a decision should be made whether to discontinue nursing or to discontinue the drug, taking into account the importance of the drug to the mother.
Infant Risk:
Risk of sedation, hypotonia, and other CNS effects in the infant. Monitor for drowsiness, poor feeding, and developmental milestones.
Pediatric Use
Safety and effectiveness in pediatric patients have not been established. Not recommended for use in this population.
Geriatric Use
Use with caution in elderly patients due to increased risk of adverse effects such as hypotension, bradycardia, and sedation. Start with lower doses and titrate slowly. Monitor closely for adverse reactions.
Clinical Information
Clinical Pearls
- Tizanidine is an alpha-2 adrenergic agonist, not a benzodiazepine or GABA-ergic agent, which differentiates its mechanism from other muscle relaxants.
- Dose titration is crucial to minimize side effects, especially hypotension and sedation. Start low and go slow.
- Abrupt discontinuation can lead to rebound hypertension, tachycardia, and increased spasticity. Taper off slowly.
- Significant drug interactions exist with CYP1A2 inhibitors (e.g., fluvoxamine, ciprofloxacin) leading to dangerously high tizanidine levels. These combinations are contraindicated.
- Food significantly affects absorption; advise patients to take consistently with or without food, but not to switch between states.
- Monitor liver function tests at baseline and periodically, especially during the first 6 months of therapy.
- Patients should be warned about the potential for severe drowsiness and dizziness, especially when initiating therapy or increasing dose.
Alternative Therapies
- Baclofen (GABA-B agonist)
- Diazepam (Benzodiazepine)
- Dantrolene (Direct-acting muscle relaxant)
- Botulinum toxin injections (for localized spasticity)
- Physical therapy
- Occupational therapy
Cost & Coverage
Average Cost:
$10 - $50 per 30 capsules (6mg)
Generic Available:
Yes
Insurance Coverage:
Tier 1 or Tier 2 (Generic)
General Drug Facts
If your symptoms or health issues persist or worsen, it is essential to contact your doctor promptly. 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 it's a good idea to check with your pharmacist. 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 detailed information about the overdose, including the substance taken, the amount, and the time it occurred.