Cyclobenzaprine: Side Effects, Uses & Monitoring
AMRIX is indicated as an adjunct to rest and physical therapy for relief of muscle spasm associated with acute, painful musculoskeletal conditions.
- Data source
- FDA labeling via NIH DailyMed (label 555ff988…)
- Label version
- current
- Last reviewed
- 2026
Reported adverse reactions
Reactions listed in current FDA labeling, with the highest frequency reported across summarized placebo-controlled trials.
| Adverse reaction (as reported in labeling) | Reported frequency* |
|---|---|
| Drowsiness | 39% |
| Headache nos | 17% |
| Dry mouth | 14% |
| Dry throat | 8% |
| Dizziness | 6% |
| Dysgeusia | 6% |
| Palpitations | 6% |
| Tremor | 6% |
| Acne nos | 6% |
| Disturbance in attention | 6% |
| Dyspepsia | 4% |
| Fatigue | 3% |
| Constipation | 3% |
| Nausea | 3% |
| Vision blurred | 3% |
| Somnolence | 2% |
| Insomnia | 0% |
*Highest percentage reported for the active moiety across placebo-controlled trial tables in current FDA labeling. Values reflect trial reporting, not your individual risk.
Labeled uses (from FDA prescribing information)
AMRIX is indicated as an adjunct to rest and physical therapy for relief of muscle spasm associated with acute, painful musculoskeletal conditions. Improvement is manifested by relief of muscle spasm and its associated signs and symptoms, namely, pain, tenderness, and limitation of motion. AMRIX should be used only for short periods (up to two or three weeks) because adequate evidence of effectiveness for more prolonged use is not available and because muscle spasm associated with acute, painful musculoskeletal conditions is generally of short duration and specific therapy for longer periods is seldom warranted. AMRIX has not been found effective in the treatment of spasticity associated with cerebral or spinal cord disease or in children with cerebral palsy.
Frequently Asked Questions
What is Cyclobenzaprine used for?
FDA labeling lists the approved uses shown above under "Labeled uses." This summary is informational; only a qualified prescriber can determine whether a medication is appropriate for you.
What are the most commonly reported side effects of Cyclobenzaprine?
The table above shows adverse reactions and the highest frequencies reported in placebo-controlled trials summarized in current FDA labeling for Cyclobenzaprine. Individual risk varies.
Does Cyclobenzaprine require lab monitoring?
Monitoring needs vary. Ask your healthcare provider whether any lab tests apply while taking Cyclobenzaprine.
Where does this information come from?
All clinical facts on this page were extracted from the current FDA-registered product labeling for this ingredient, published by manufacturers through NIH DailyMed. See the source link below.
Medical disclaimer: Educational content extracted from public FDA labeling. Not medical advice. Always consult a qualified healthcare professional before starting, stopping, or changing any medication.