Cyclobenzaprine is a muscle relaxant. It works by blocking nerve impulses (or pain sensations) that are sent to your brain.
Cyclobenzaprine is used together with rest and physical therapy to treat skeletal muscle conditions such as pain or injury.
Take this medication by mouth with or without food as directed by your doctor. Do not increase your dose or use this drug more often or for longer than prescribed. Your condition will not improve any faster, and your risk of side effects will increase.
The dosage is based on your medical condition and response to treatment. This medication should only be used short-term (for 3 weeks or less) unless directed by your doctor.
Tell your doctor if your condition persists after 2 to 3 weeks or if it worsens.
More common side effects
The more common side effects of cyclobenzaprine can include:
If these effects are mild, they may go away within a few days or a couple of weeks. If they’re more severe or don’t go away, talk to your doctor or pharmacist.
Serious side effects
Call your doctor right away if you have serious side effects. Call 911 if your symptoms feel life-threatening or if you think you’re having a medical emergency. Serious side effects and their symptoms can include the following:
Heart problems. Symptoms can include:
heart palpitations (fast or irregular heartbeat)
trouble speaking or understanding
loss of control or numbness in your face, arms, or legs
trouble seeing in one or both eyes
Serotonin syndrome. Symptoms can include:
agitation (a feeling of aggravation or restlessness)
hallucinations (hearing or seeing something that isn’t there)
Store cyclobenzaprine at 77°F (25°C).
Keep it away from light.
Don’t store it in moist or damp areas, such as bathrooms.
Some products that may interact with this drug include: tricyclic antidepressants (such as amitriptyline, imipramine).
Taking MAO inhibitors with this medication may cause a serious (possibly fatal) drug interaction. Avoid taking MAO inhibitors (isocarboxazid, linezolid, methylene blue, moclobemide, phenelzine, procarbazine, rasagiline, safinamide, selegiline, tranylcypromine) during treatment with this medication. Most MAO inhibitors should also not be taken for two weeks before treatment with this medication. Ask your doctor when to start or stop taking this medication.
Before using this medication, report the use of drugs that increase serotonin, including street drugs (such as MDMA/"ecstasy"), St. Johns wort, certain antidepressants (including SSRIs such as fluoxetine/paroxetine, SNRIs such as duloxetine/venlafaxine), tramadol, among others.
Tell your doctor or pharmacist if you are taking other products that cause drowsiness such as opioid pain or cough relievers (such as codeine, hydrocodone), alcohol, marijuana (cannabis), drugs for sleep or anxiety (such as alprazolam, lorazepam, zolpidem), other muscle relaxants (such as carisoprodol, methocarbamol), or antihistamines (such as cetirizine, diphenhydramine).
If someone has overdosed and has serious symptoms such as passing out or trouble breathing, call 911. Otherwise, call a poison control center right away. US residents can call their local poison control center at 1-800-222-1222. Canada residents can call a provincial poison control center. Symptoms of overdose may include: fast/irregular heartbeat, fainting, severe drowsiness, slurred speech, seizures, mental/mood changes (such as confusion, hallucinations).