Cyclobenzaprine Hydrochloride (4 brand names, 2 dosage forms, 2 routes)
Available dosage forms: CAPSULE, EXTENDED RELEASE, TABLET.
Routes of administration: ORAL, SUBLINGUAL.
Brand Names
- AMRIX
- CYCLOBENZAPRINE HYDROCHLORIDE
- FLEXERIL
- TONMYA
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 has not been found effective in the treatment of spasticity associated with cerebral or spinal cord disease, or in children with cerebral palsy.
Dosage and Administration
For most patients, the recommended dose of cyclobenzaprine hydrochloride tablets, USP is 5 mg three times a day. Based on individual patient response, the dose may be increased to 10 mg three times a day. Use of cyclobenzaprine hydrochloride tablets, USP for periods longer than two or three weeks is not recommended. (see INDICATIONS AND USAGE). Less frequent dosing should be considered for hepatically impaired or elderly patients (see PRECAUTIONS, Impaired Hepatic Function, and Use in the Elderly).
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.
Adverse Reactions
Incidence of most common adverse reactions in the 2 double-blind *, placebo-controlled 5 mg studies (incidence of > 3% on cyclobenzaprine hydrochloride 5 mg): *Note: Cyclobenzaprine hydrochloride10 mg data are from one clinical trial. cyclobenzaprine hydrochloride 5 mg and placebo data are from two studies. 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: 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
Drug Interactions
Cyclobenzaprine hydrochloride 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.
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 maydevelop rapidly after cyclobenzaprine overdose; therefore, hospital monitoring is required as soon as possible. The acute oral LD 50of cyclobenzaprine hydrochloride is approximately 338 and 425 mg/kg in mice and rats, respectively.