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- Cyclobenzaprine vs. Zanaflex: What's the difference?
- What is cyclobenzaprine? What is Zanaflex?
- What are the side effects of cyclobenzaprine and Zanaflex?
- What is the dosage of cyclobenzaprine vs. Zanaflex?
- What drugs interact with cyclobenzaprine and Zanaflex?
- Are cyclobenzaprine and Zanaflex safe to use while pregnant or breastfeeding?
Cyclobenzaprine vs. Zanaflex: What's the difference?
- Cyclobenzaprine and Zanaflex (tizanidine) are muscle relaxants used to relieve muscle spasms associated with painful muscle and skeletal conditions.
- Cyclobenzaprine is used with rest and physical therapy for short-term relief of muscle spasms associated with acute painful muscle and skeletal conditions while Zanaflex is used for the treatment and management of skeletal muscle spasticity due to chronic conditions such as multiple sclerosis or spinal cord injury.
- Brand names for cyclobenzaprine include Flexeril, Amrix, and Fexmid.
- Side effects of cyclobenzaprine and Zanaflex that are similar include dry mouth, fatigue, dizziness, constipation, and blurred vision.
- Side effects of cyclobenzaprine that are different from Zanaflex include drowsiness, headaches, nausea, unpleasant taste, nervousness, confusion, acid reflux, and abdominal pain or discomfort.
- Side effects of Zanaflex that are different from cyclobenzaprine include low blood pressure, sleepiness, and weakness.
What is cyclobenzaprine? What is Zanaflex?
Cyclobenzaprine is a muscle relaxant used with rest and physical therapy for short-term relief (up to two to three weeks) of muscle spasms associated with acute painful muscle and skeletal conditions. Cyclobenzaprine relieves muscle spasm when the spasm that results from local problems in the muscle itself and not from the nerves controlling the muscles. Cyclobenzaprine accomplishes its helpful effect through a complex mechanism within the nervous system, most likely in the brainstem.
Zanaflex (tizanidine) is a skeletal muscle relaxant used for the treatment and management of skeletal muscle spasticity, typically resulting from neurological problems. Spasticity may be due to multiple sclerosis or spinal cord injury. It works on alpha 2 receptors in the central nervous system (brain and spinal cord) and blocks nerve impulses from reaching muscles, which produces muscle relaxation.
What are the side effects of cyclobenzaprine and Zanaflex?
The most common side effects of cyclobenzaprine include:
Other reported side effects include:
- Blurred vision,
- Unpleasant taste
- Acid reflux
- Abdominal pain or discomfort
Possible serious side effects include:
Abrupt cessation after prolonged therapy may cause withdrawal symptoms such as headaches, nausea, and weakness.
Common side effects of tizanidine include:
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What is the dosage of cyclobenzaprine vs. Zanaflex?
The recommended dose of cyclobenzaprine dose is 5 or 10 mg three times daily using immediate release tablets or 15 or 30 mg once daily using extended release tablets.
Initially take 2 - 4 mg by mouth every 6 to 8 hours for up to 3 doses in 24 hours. Increase by 2 to 4 mg until satisfactory response is achieved; however, the maximum dose is 36 mg per day.
What drugs interact with cyclobenzaprine and Zanaflex?
- Cyclobenzaprine is chemically related to the tricyclic class of antidepressants, for example, amitriptyline (Elavil, Endep), nortriptyline Pamelor). As such, it should not be taken with or within two weeks of any monoamine oxidase (MAO) inhibitor, for example, isocarboxazid (Marplan), phenelzine (Nardil), tranylcypromine (Parnate), and procarbazine (Matulane). High fever, convulsions, and even death can occur when these drugs are used together.
- Cyclobenzaprine interacts with other medications and drugs that slow the brain's processes, such as
Tizanidine should not be used with:
- ciprofloxacin (Cipro),
- amiodarone (Cordarone),
- cimetidine (Tagamet),
- oral contraceptives,
- acyclovir (Zovirax), and
- fluvoxamine (Luvox).
These medications can slow down the breakdown of tizanidine and lead to increased sedation, drowsiness and slowed reflexes.
Tizanidine should be used with caution with medications like:
- alprazolam (Xanax),
- clonazepam (Klonopin),
- diazepam (Valium),
- zolpidem (Ambien),
- oxycodone (Roxicodone),
- hydromorphone (Dilaudid),
- amitriptyline (Elavil),
- nortriptyline (Pamelor) and
These medications can further increase the side effects of tizanidine.
Are cyclobenzaprine and Zanaflex safe to use while pregnant or breastfeeding?
There are no adequate studies of cyclobenzaprine in pregnant women. However, studies in animals suggest no important effects on the fetus. Cyclobenzaprine therefore can be used in pregnancy if the physician feels that it is necessary.
It is not known whether cyclobenzaprine is secreted in milk. However, since it is related to the tricyclic antidepressants, some of which are excreted in breast milk, caution is advised in using this medication in women who are breastfeeding.
There are no adequate studies done on tizanidine to determine safe and effective use in pregnant women.
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Flexeril (cyclobenzaprine) and Zanaflex (tizanidine) are muscle relaxants used to relieve muscle spasms associated with painful muscle and skeletal conditions. Cyclobenzaprine is used with rest and physical therapy for short-term relief of muscle spasms associated with acute painful muscle and skeletal conditions while Zanaflex is used for the treatment and management of skeletal muscle spasticity due to chronic conditions such as multiple sclerosis or spinal cord injury.
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Muscle spasms are involuntary muscle contractions that come on suddenly and are usually quite painful. Dehydration, doing strenuous exercise in a hot environment, prolonged muscle use, and certain diseases of the nervous system may cause muscle spasms. Symptoms and signs of a muscle spasm include an acute onset of pain and a possible bulge seen or felt beneath the skin where the muscle is located. Gently stretching the muscle usually resolves a muscle spasm.
Muscle cramps are involuntarily and forcibly contracted muscles that do not relax. Extremely common, any muscles that have voluntary control, including some organs, are subject to cramp. Since there is such variety in the types of muscle cramps that can occur, many causes and preventative medications are known. Stretching is the most common way to stop or prevent most muscle cramps.
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Muscle pain (myofascial pain syndrome) is muscle pain in the body's soft tissues due to injury or strain. Symptoms include muscle pain with tender points and fatigue. Treatment usually involves physical therapy, massage therapy, or trigger point injection.
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