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Quick facts
- How it is given
- oral
- Type
- human prescription drug
- RxNorm ID
- 828348
We do not publish dosing. How much of this medicine to take, how often, and for how long depends on your age, weight, kidney and liver function, other conditions and other medicines. That is a decision for the person who prescribes or dispenses it. Follow the directions on your own pack and ask your pharmacist if anything is unclear.
What it is used to treat
INDICATIONS AND USAGE Cyclobenzaprine hydrochloride tablets, USP are 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, limitation of motion, and restriction in activities of daily living. Cyclobenzaprine hydrochloride tablets, USP 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. Cyclobenzaprine hydrochloride tablets, USP have not been found effective in the treatment of spasticity associated with cerebral or spinal cord disease, or in children with cerebral palsy.
About this medicine
DESCRIPTION Cyclobenzaprine hydrochloride, USP is a white, crystalline tricyclic amine salt with the molecular formula C 20 H 21 N • HCl and a molecular weight of 311.9. It has a melting point of 217ºC, and a pK a of 8.47 at 25ºC. It is freely soluble in water and alcohol, sparingly soluble in isopropanol, and insoluble in hydrocarbon solvents. If aqueous solutions are made alkaline, the free base separates. Cyclobenzaprine hydrochloride is designated chemically as 3-( 5H -dibenzo[ a , d ] cyclohepten-5-ylidene)- N, N -dimethyl-1-propanamine hydrochloride, and has the following structural formula: Cyclobenzaprine hydrochloride is supplied as 5 mg or 10 mg tablets for oral administration. Each tablet contains the following inactive ingredients: croscarmellose sodium, hypromellose, lactose monohydrate, magnesium stearate, polyethylene glycol, pregelatinized starch (maize) and titanium dioxide. In addition 5 mg also contains D&C yellow #10 aluminum lake and FD&C yellow #6 aluminum lake and 10 mg also contains yellow iron oxide. FDA approved dissolution test specifications differ from USP. Chemical Structure
Who should not take it
CONTRAINDICATIONS Hypersensitivity to any component of this product. Concomitant use of monoamine oxidase (MAO) inhibitors or within 14 days after their discontinuation. Hyperpyretic crisis seizures, and deaths have occurred in patients receiving cyclobenzaprine (or structurally similar tricyclic antidepressants) concomitantly with MAO inhibitor drugs. Acute recovery phase of myocardial infarction, and patients with arrhythmias, heart block or conduction disturbances, or congestive heart failure. Hyperthyroidism.
Warnings
WARNINGS Serotonin Syndrome The development of a potentially life-threatening serotonin syndrome has been reported with cyclobenzaprine hydrochloride when used in combination with other drugs, such as selective serotonin reuptake inhibitors (SSRIs), serotonin norepinephrine reuptake inhibitors (SNRIs), tricyclic antidepressants (TCAs), tramadol, bupropion, meperidine, verapamil, or MAO inhibitors. The concomitant use of cyclobenzaprine hydrochloride with MAO inhibitors is contraindicated (see CONTRAINDICATIONS ). Serotonin syndrome symptoms may include mental status changes (e.g., confusion, agitation, hallucinations), autonomic instability (e.g., diaphoresis, tachycardia, labile blood pressure, hyperthermia), neuromuscular abnormalities (e.g., tremor, ataxia, hyperreflexia, clonus, muscle rigidity), and/or gastrointestinal symptoms (e.g., nausea, vomiting, diarrhea). Treatment with cyclobenzaprine hydrochloride and any concomitant serotonergic agents should be discontinued immediately if the above reactions occur and supportive symptomatic treatment should be initiated. If concomitant treatment with cyclobenzaprine hydrochloride and other serotonergic drugs is clinically warranted, careful observation is advised, particularly during treatment initiation or dose increases (see PRECAUTIONS, Drug Interactions ). Cyclobenzaprine is closely related to the tricyclic antidepressants, e.g., amitriptyline and imipramine. In short term studies for indications other than muscle spasm associated with acute musculoskeletal conditions, and usually at doses somewhat greater than those recommended for skeletal muscle spasm, some of the more serious central nervous system reactions noted with the tricyclic antidepressants have occurred (see WARNINGS , below, and ADVERSE REACTIONS ). Tricyclic antidepressants have been reported to produce arrhythmias, sinus tachycardia, prolongation of the conduction time leading to myocardial infarction and stroke. Cyclobenzaprine hydrochloride may enhance the effects of alcohol, barbiturates, and other CNS depressants.
Reported side effects
ADVERSE REACTIONS Incidence of most common adverse reactions in the 2 double-blind 3 , placebo-controlled 5 mg studies (incidence of > 3% on cyclobenzaprine hydrochloride 5 mg): Cyclobenzaprine Hydrochloride 5 mg Cyclobenzaprine Hydrochloride 10 mg Placebo N=464 N=249 N=469 Drowsiness 29% 38% 10% Dry Mouth 21% 32% 7% Fatigue 6% 6% 3% Headache 5% 5% 8% Adverse reactions which were reported in 1% to 3% of the patients were: abdominal pain, acid regurgitation, constipation, diarrhea, dizziness, nausea, irritability, mental acuity decreased, nervousness, upper respiratory infection, and pharyngitis. The following list of adverse reactions is based on the experience in 473 patients treated with cyclobenzaprine hydrochloride 10 mg in additional controlled clinical studies, 7607 patients in the postmarketing surveillance program, and reports received since the drug was marketed. The overall incidence of adverse reactions among patients in the surveillance program was less than the incidence in the controlled clinical studies. The adverse reactions reported most frequently with cyclobenzaprine hydrochloride were drowsiness, dry mouth and dizziness. The incidence of these common adverse reactions was lower in the surveillance program than in the controlled clinical studies: 3 Note: Cyclobenzaprine hydrochloride 10 mg data are from one clinical trial. Cyclobenzaprine hydrochloride 5 mg and placebo data are from two studies. Clinical Studies With Cyclobenzaprine Hydrochloride 10 mg Surveillance Program With Cyclobenzaprine Hydrochloride 10 mg Drowsiness 39% 16% Dry Mouth 27% 7% Dizziness 11% 3% Among the less frequent adverse reactions, there was no appreciable difference in incidence in controlled clinical studies or in the surveillance program. Adverse reactions which were reported in 1% to 3% of the patients were: fatigue/tiredness, asthenia, nausea, constipation, dyspepsia, unpleasant taste, blurred vision, headache, nervousness, and confusion. The following adverse reactions have been reported in post-marketing experience or with an incidence of less than 1% of patients in clinical trials with the 10 mg tablet: Body as a Whole: Syncope; malaise. […]
Interactions with other medicines
Drug Interactions Cyclobenzaprine may have life-threatening interactions with MAO inhibitors (see CONTRAINDICATIONS ). Postmarketing cases of serotonin syndrome have been reported during combined use of cyclobenzaprine hydrochloride and other drugs, such as SSRIs, SNRIs, TCAs, tramadol, bupropion, meperidine, verapamil, or MAO inhibitors. If concomitant treatment with cyclobenzaprine hydrochloride and other serotonergic drugs is clinically warranted, careful observation is advised, particularly during treatment initiation or dose increases (see WARNINGS ). Cyclobenzaprine hydrochloride may enhance the effects of alcohol, barbiturates, and other CNS depressants. Tricyclic antidepressants may block the antihypertensive action of guanethidine and similarly acting compounds. Tricyclic antidepressants may enhance the seizure risk in patients taking tramadol. 2 2 ULTRAM ® (tramadol HCl tablets, PriCara, Division of Ortho-McNeil-Janssen Pharmaceuticals, Inc.) ULTRACET ® (tramadol HCl and acetaminophen tablets, PriCara, Division of Ortho-McNeil-Janssen Pharmaceuticals, Inc.)
If too much is taken
OVERDOSAGE Although rare, deaths may occur from overdosage with cyclobenzaprine hydrochloride. Multiple drug ingestion (including alcohol) is common in deliberate cyclobenzaprine overdose. As management of overdose is complex and changing, it is recommended that the physician contact a poison control center for current information on treatment. Signs and symptoms of toxicity may develop rapidly after cyclobenzaprine overdose; therefore, hospital monitoring is required as soon as possible. The acute oral LD 50 of cyclobenzaprine hydrochloride is approximately 338 and 425 mg/kg in mice and rats, respectively. Manifestations The most common effects associated with cyclobenzaprine overdose are drowsiness and tachycardia. Less frequent manifestations include tremor, agitation, coma, ataxia, hypertension, slurred speech, confusion, dizziness, nausea, vomiting, and hallucinations. Rare but potentially critical manifestations of overdose are cardiac arrest, chest pain, cardiac dysrhythmias, severe hypotension, seizures, and neuroleptic malignant syndrome. Changes in the electrocardiogram, particularly in QRS axis or width, are clinically significant indicators of cyclobenzaprine toxicity. Other potential effects of overdosage include any of the symptoms listed under ADVERSE REACTIONS . Management General As management of overdose is complex and changing, it is recommended that the physician contact a poison control center for current information on treatment. In order to protect against the rare but potentially critical manifestations described above, obtain an ECG and immediately initiate cardiac monitoring. Protect the patient’s airway, establish an intravenous line and initiate gastric decontamination. Observation with cardiac monitoring and observation for signs of CNS or respiratory depression, hypotension, cardiac dysrhythmias and/or conduction blocks, and seizures is necessary. If signs of toxicity occur at any time during this period, extended monitoring is required. Monitoring of plasma drug levels should not guide management of the patient. Dialysis is probably of no value because of low plasma concentrations of the drug. […]
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This page is built from the openFDA record of the U.S. Food and Drug Administration's approved labelling for this product, effective 1 April 2026. Label text has been shortened and reformatted for readability; safety wording has not been altered in meaning. FDA labelling describes products approved in the United States — brand names, strengths, formulations and approved uses may differ in your country. Always read the leaflet that comes with your own pack. PocketsInfo is not affiliated with, and is not endorsed by, the FDA. Retrieved 2026-07-30.