Pill Identifier App

Cyclobenzaprine Side Effects

Not all side effects for cyclobenzaprine may be reported. You should always consult a doctor or healthcare professional for medical advice. Side effects can be reported to the FDA here.

For the Consumer

Applies to cyclobenzaprine: oral capsule extended release, oral suspension, oral tablet

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.

Stop taking cyclobenzaprine and get emergency help immediately if any of the following effects occur:

  • Changes in the skin color of the face
  • fast or irregular breathing
  • large swellings that look like hives on the face, eyelids, mouth, lips, and/or tongue
  • puffiness or swelling of the eyelids or the area around the eyes
  • shortness of breath, troubled breathing, tightness in chest, and/or wheezing
  • skin rash, hives, or itching

Check with your doctor immediately if any of the following side effects occur while taking cyclobenzaprine:

  • Fainting
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)

Check with your doctor as soon as possible if any of the following side effects occur while taking cyclobenzaprine:

  • Clumsiness or unsteadiness
  • confusion
  • mental depression or other mood or mental changes
  • 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

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:

More common
  • Blurred vision
  • dizziness or lightheadedness
  • drowsiness
  • dryness of mouth
Less common or rare
  • Bloated feeling or gas, indigestion, nausea or vomiting, or stomach cramps or pain
  • constipation
  • diarrhea
  • excitement or nervousness
  • frequent urination
  • general feeling of discomfort or illness
  • headache
  • muscle twitching
  • numbness, tingling, pain, or weakness in hands or feet
  • pounding heartbeat
  • problems in speaking
  • trembling
  • trouble in 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

Nervous system

Elderly patients may be particularly susceptible to the sedation and confusion which may accompany cyclobenzaprine therapy.

Nervous system side effects are common and include drowsiness in up to 40% of treated patients and dizziness in up to 11%. Fatigue, asthenia, headache, nervousness, blurred vision, and confusion have also been reported.


Other side effects have included anticholinergic effects such as dry mouth (in as many as 27% of treated patients), and, less frequently, dry skin, blurry vision, constipation, and an organic brain syndrome. Paradoxical sweating has also been reported.


Psychiatric side effects including mania and psychosis have been reported rarely. A case of hallucinations has also been reported.


Hypersensitivity side effects have included rash, angioedema, and pruritus. Anaphylaxis has been reported rarely.


Cardiovascular side effects have included cardiac arrhythmias, tachycardia, and hypotension.

Disclaimer: Every effort has been made to ensure that the information provided is accurate, up-to-date and complete, but no guarantee is made to that effect. In addition, the drug information contained herein may be time sensitive and should not be utilized as a reference resource beyond the date hereof. This material does not endorse drugs, diagnose patients, or recommend therapy. This information is a reference resource designed as supplement to, and not a substitute for, the expertise, skill , knowledge, and judgement of healthcare practitioners in patient care. The absence of a warning for a given drug or combination thereof in no way should be construed to indicate safety, effectiveness, or appropriateness for any given patient. Drugs.com does not assume any responsibility for any aspect of healthcare administered with the aid of materials provided. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the substances you are taking, check with your doctor, nurse, or pharmacist.