Cyclobenzaprine ER

generic for Amrix

Cyclobenzaprine ER Side Effects

Drowsiness, dizziness, dry mouth, or tiredness may occur. If any of these effects persist or worsen, tell your doctor or pharmacist promptly.

Remember that your doctor has prescribed this medication because he or she has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.

Tell your doctor right away if you have any serious side effects, including: fast/irregular heartbeat, mental/mood changes (such as confusion, hallucinations).

A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.

This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.

In the US -

Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch.

In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.
  • SIADH syndrome
  • drug-induced psychosis
  • acute confusion
  • paranoid disorder
  • libido changes
  • agitation
  • depression
  • extrapyramidal disease
  • neuroleptic malignant syndrome
  • serotonin syndrome
  • CNS toxicity
  • blurred vision
  • tinnitus
  • hypertension
  • acute myocardial infarction
  • heart block
  • cardiac arrhythmia
  • cerebrovascular accident
  • hypotension
  • vasodilation of blood vessels
  • bronchospastic pulmonary disease
  • parotitis
  • xerostomia
  • dyspepsia
  • gastrointestinal irritation
  • constipation
  • hepatitis
  • cholestasis
  • gynecomastia
  • galactorrhea not associated with childbirth
  • allergic dermatitis
  • pruritus of skin
  • acne vulgaris
  • urticaria
  • muscle weakness
  • drowsy
  • hallucinations
  • syncope
  • seizure disorder
  • vertigo
  • dizziness
  • insomnia
  • fatigue
  • hyperhidrosis
  • tremor
  • muscle fasciculation
  • dysgeusia
  • ataxia
  • skin rash
  • edema
  • anorexia
  • headache disorder
  • dysarthria
  • palpitations
  • dyspnea
  • chest pain
  • nausea
  • vomiting
  • flatulence
  • diarrhea
  • dysuria
  • urinary retention
  • increased urinary frequency
  • abnormal electroencephalogram
  • abnormal hepatic function tests
  • nervousness
  • anaphylaxis
  • angioedema
  • paresthesia
  • malaise
  • acute abdominal pain
  • Bell's palsy
  • jaundice
  • disturbance of attention
  • loss of taste
  • DRESS syndrome
  • tachycardia

Drug Interactions

Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval.

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. John's 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).

Check the labels on all your medicines (such as allergy or cough-and-cold products) because they may contain ingredients that cause drowsiness. Ask your pharmacist about using those products safely.