Cyclobenzaprine Side Effects
Medically reviewed by Drugs.com. Last updated on Feb 14, 2023.
Applies to cyclobenzaprine: oral capsule extended release, oral suspension, oral tablet.
Serious side effects of Cyclobenzaprine
Along with its needed effects, cyclobenzaprine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.
Check with your doctor immediately if any of the following side effects occur while taking cyclobenzaprine:
- Clumsiness or unsteadiness
- mental depression
- problems in urinating
- ringing or buzzing in the ears
- skin rash, hives, or itching occurring without other symptoms of an allergic reaction listed above
- unusual thoughts or dreams
- yellow eyes or skin
Get emergency help immediately if any of the following symptoms of overdose occur while taking cyclobenzaprine:
Symptoms of overdose
- Convulsions (seizures)
- drowsiness (severe)
- dry, hot, flushed skin
- fast or irregular heartbeat
- hallucinations (seeing, hearing, or feeling things that are not there)
- increase or decrease in body temperature
- troubled breathing
- unexplained muscle stiffness
- unusual nervousness or restlessness (severe)
- vomiting (occurring together with other symptoms of overdose)
Other side effects of Cyclobenzaprine
Some side effects of cyclobenzaprine may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects.
Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:
- Blurred vision
- dizziness, drowsiness, or lightheadedness
- dryness of the mouth
Less common or rare
- Bloated feeling or gas, indigestion, nausea or vomiting, or stomach cramps or pain
- excitement or nervousness
- frequent urination
- general feeling of discomfort or illness
- muscle twitching
- numbness, tingling, pain, or weakness in hands or feet
- pounding heartbeat
- problems in speaking
- trouble sleeping
- unpleasant taste or other taste changes
- unusual muscle weakness
- unusual tiredness
For Healthcare Professionals
Applies to cyclobenzaprine: compounding powder, oral capsule extended release, oral tablet, oral and topical kit.
Elderly patients may be particularly susceptible to the sedation and confusion which may accompany cyclobenzaprine therapy.[Ref]
Very common (10% or more): Drowsiness (up to 38%)
Common (1% to 10%): Dizziness, somnolence
Postmarketing reports: Headache, serotonin syndrome, seizures, ataxia, tremors, hypertonia, convulsions, abnormal sensations, paresthesia, ageusia[Ref]
Common (1% to 10%): Irritability, mental acuity decreased, nervousness
Postmarketing reports: Nervousness, confusion, disorientation, insomnia, depressed mood, anxiety, agitation, psychosis, abnormal thinking and dreaming, hallucinations, excitement[Ref]
Very common (10% or more): Dry mouth (up to 32%)
Common (1% to 10%): Constipation, nausea, dyspepsia, abdominal pain, acid regurgitation, diarrhea
Common (1% to 10%): Fatigue
Postmarketing reports: Asthenia, malaise, vertigo[Ref]
Postmarketing reports: Sweating[Ref]
Postmarketing reports: Urinary frequency and/or retention[Ref]
Postmarketing reports: Local weakness, dysarthria, muscle twitching[Ref]
Postmarketing reports: Blurred vision, diplopia, tinnitus[Ref]
Frequently asked questions
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More about cyclobenzaprine
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Related treatment guides
1. Product Information. Amrix (cyclobenzaprine). A-S Medication Solutions. 2016.
2. Product Information. Flexeril (cyclobenzaprine). Merck & Co., Inc. 2001.
Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.
Some side effects may not be reported. You may report them to the FDA.