cyclobenzaprine hydrochloride

Indications and Usage Section INDICATIONS AND USAGE Cyclobenzaprine hydrochloride tablets 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 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 have 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 Section DOSAGE AND ADMINISTRATION For most patients, the recommended dose of cyclobenzaprine hydrochloride tablets 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 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 Section 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 HCl 5 mg): Cyclobenzaprine HCl Tablets Cyclobenzaprine HCl Tablets Placebo 5 mg 10 mg N=464 N=249 N=469 Drowsiness 29% 38% 10% Dry Mouth 21% 32% 7% Fatigue 6% 6% 3% Headache 5% 5% 8% ‡ Note: Cyclobenzaprine HCl Tablets 10 mg data are from one clinical trial. Cyclobenzaprine HCl Tablets 5 mg and placebo data are from two studies. 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 HCl 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 HCl 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 Surveillance Program with Cyclobenzaprine HCl Tablets 10 mg Cyclobenzaprine HCl Tablets 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 postmarketing 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. Cardiovascular: Tachycardia; arrhythmia; vasodilatation; palpitation; hypotension. Digestive: Vomiting; anorexia; diarrhea; gastrointestinal pain; gastritis; thirst; flatulence; edema of the tongue; abnormal liver function and rare reports of hepatitis, jaundice and cholestasis. Hypersensitivity: Anaphylaxis; angioedema; pruritus; facial edema; urticaria; rash. Musculoskeletal: Local weakness. Nervous System and Psychiatric: Seizures, ataxia; vertigo; dysarthria; tremors; hypertonia; convulsions; muscle twitching; disorientation; insomnia; depressed mood; abnormal sensations; anxiety; agitation; psychosis, abnormal thinking and dreaming; hallucinations; excitement; paresthesia; diplopia, serotonin syndrome. Skin: Sweating. Special Senses: Ageusia; tinnitus. Urogenital: Urinary frequency and/or retention. Causal Relationship Unknown Other reactions, reported rarely for cyclobenzaprine HCl under circumstances where a causal relationship could not be established or reported for other tricyclic drugs, are listed to serve as alerting information to physicians: Body as a Whole: Chest pain; edema. Cardiovascular: Hypertension; myocardial infarction; heart block; stroke. Digestive: Paralytic ileus, tongue discoloration; stomatitis; parotid swelling. Endocrine: Inappropriate ADH syndrome. Hematic and Lymphatic: Purpura; bone marrow depression; leukopenia; eosinophilia; thrombocytopenia. Metabolic, Nutritional and Immune: Elevation and lowering of blood sugar levels; weight gain or loss. Musculoskeletal: Myalgia. Nervous System and Psychiatric: Decreased or increased libido; abnormal gait; delusions; aggressive behavior; paranoia; peripheral neuropathy; Bell’s palsy; alteration in EEG patterns; extrapyramidal symptoms. Respiratory: Dyspnea. Skin: Photosensitization; alopecia. Urogenital: Impaired urination; dilatation of urinary tract; impoten …

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 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. Carcinogenesis, mutagenesis, impairment of fertility In rats treated with cyclobenzaprine hydrochloride for up to 67 weeks at doses of approximately 5 to 40 times the maximum recommended human dose, pale, sometimes enlarged, livers were noted and there was a dose-related hepatocyte vacuolation with lipidosis. In the higher dose groups this microscopic change was seen after 26 weeks and even earlier in rats which died prior to 26 weeks; at lower doses, the change was not seen until after 26 weeks. Cyclobenzaprine did not affect the onset, incidence or distribution of neoplasia in an 81-week study in the mouse or in a 105-week study in the rat. At oral doses of up to 10 times the human dose, cyclobenzaprine did not adversely affect the reproductive performance or fertility of male or female rats. Cyclobenzaprine did not demonstrate mutagenic activity in the male mouse at dose levels of up to 20 times the human dose. Pregnancy Teratogenic Effects. Pregnancy Category B Reproduction studies have been performed in rats, mice and rabbits at doses up to 20 times the human dose, and have revealed no evidence of impaired fertility or harm to the fetus due to cyclobenzaprine. There are, however, no adequate and well-controlled studies in pregnant women. Because animal reproduction studies are not always predictive of human response, this drug should be used during pregnancy only if clearly needed. Nursing Mothers It is not known whether this drug is excreted in human milk. Because cyclobenzaprine is closely related to the tricyclic antidepressants, some of which are known to be excreted in human milk, caution should be exercised when cyclobenzaprine hydrochloride is administered to a nursing woman. Pediatric Use Safety and effectiveness of cyclobenzaprine in pediatric patients below 15 years of age have not been established. Use in the Elderly The plasma concentration of cyclobenzaprine is increased in the elderly (see CLINICAL PHARMACOLOGY: Pharmacokinetics: Elderly .) The elderly may also be more at risk for CNS adverse events such as hallucinations and confusion, cardiac events resulting in falls or other sequelae, drug-drug and drug-disease interactions. For these reasons, in the elderly, cyclobenzaprine should be used only if clearly needed. In such patients cyclobenzaprine hydrochloride should be initiated with a 5 mg dose and titrated slowly upward.

DESCRIPTION Cyclobenzaprine hydrochloride, USP is a white to off-white, odorless, crystalline powder with the molecular formula C 20 H 21 N•HCl and a molecular weight of 311.85. It has a melting point between 215°C to 219°C and a pKa of 8.47. It is freely soluble in water, in alcohol, and in methanol, sparingly soluble in isopropanol, slightly soluble in chloroform and in methylene chloride, insoluble in n-Hexane. Cyclobenzaprine HCl, USP 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 USP, 5 mg is supplied as a 5 mg tablet for oral administration. Cyclobenzaprine hydrochloride USP, 7.5 mg is supplied as a 7.5 mg tablet for oral administration. Cyclobenzaprine hydrochloride USP, 10 mg is supplied as a 10 mg tablet for oral administration. Cyclobenzaprine hydrochloride tablets, USP 5 mg contain the following inactive ingredients: colloidal silicon dioxide, croscarmellose sodium, hypromellose, hydroxypropyl cellulose, lactose monohydrate, magnesium stearate, microcrystalline cellulose, talc, titanium dioxide and triacetin. Cyclobenzaprine hydrochloride tablets, USP 7.5 mg contain the following inactive ingredients: colloidal silicon dioxide, croscarmellose sodium, hypromellose, hydroxypropyl cellulose, lactose monohydrate, magnesium stearate, microcrystalline cellulose, talc, titanium dioxide, triacetin and yellow iron oxide. Cyclobenzaprine hydrochloride tablets, USP 10 mg contain the following inactive ingredients: colloidal silicon dioxide, croscarmellose sodium, FD&C Blue No. 2 Aluminium Lake, hypromellose, hydroxypropyl cellulose, lactose monohydrate, magnesium stearate, microcrystalline cellulose, talc, titanium dioxide, triacetin and yellow iron oxide. FDA approved organic impurities test acceptance criterion differs from the USP organic impurities test acceptance criterion in Cyclobenzaprine Hydrochloride Tablets. Image

OVERDOSAGE Although rare, deaths may occur from overdosage with cyclobenzaprine. 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 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. The NorthStar Rx LLC toll free number to report adverse events is 1-800-206-7821. 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. Gastrointestinal Decontamination All patients suspected of an overdose with cyclobenzaprine should receive gastrointestinal decontamination. This should include large volume gastric lavage followed by activated charcoal. If consciousness is impaired, the airway should be secured prior to lavage and emesis is contraindicated. Cardiovascular A maximal limb-lead QRS duration of ≥ 0.10 seconds may be the best indication of the severity of the overdose. Serum alkalinization, to a pH of 7.45 to 7.55, using intravenous sodium bicarbonate and hyperventilation (as needed), should be instituted for patients with dysrhythmias and/or QRS widening. A pH > 7.60 or a pCO 2 < 20 mmHg is undesirable. Dysrhythmias unresponsive to sodium bicarbonate therapy/hyperventilation may respond to lidocaine, bretylium or phenytoin. Type 1A and 1C antiarrhythmics are generally contraindicated (e.g., quinidine, disopyramide, and procainamide). CNS In patients with CNS depression, early intubation is advised because of the potential for abrupt deterioration. Seizures should be controlled with benzodiazepines or, if these are ineffective, other anticonvulsants (e.g., phenobarbital, phenytoin). Physostigmine is not recommended except to treat life-threatening symptoms that have been unresponsive to other therapies, and then only in close consultation with a poison control center. Psychiatric Follow-up Since overdosage is often deliberate, patients may attempt suicide by other means during the recovery phase. Psychiatric referral may be appropriate. Pediatric Management The principles of management of child and adult overdosages are similar. It is strongly recommended that the physician contact the local poison control center for specific pediatric treatment.

HOW SUPPLIED Cyclobenzaprine Hydrochloride Tablets USP, 5 mg are round, white, unscored, film-coated tablets debossed W51 on one side and TV on the other side and supplied as follows: Bottles of 1 NDC 76420-269-01 (repackaged from NDC 0093-3420-01) Bottles of 2 NDC 76420-269-02 (repackaged from NDC 0093-3420-01) Bottles of 7 NDC 76420-269-07 (repackaged from NDC 0093-3420-01) Bottles of 15 NDC 76420-269-15 (repackaged from NDC 0093-3420-01) Bottles of 20 NDC 76420-269-20 (repackaged from NDC 0093-3420-01) Bottles of 30 NDC 76420-269-30 (repackaged from NDC 0093-3420-01) Bottles of 60 NDC 76420-269-60 (repackaged from NDC 0093-3420-01) Bottles of 90 NDC 76420-269-90 (repackaged from NDC 0093-3420-01) Bottles of 100 NDC 76420-269-10 (relabeled from NDC 0093-3420-01) Cyclobenzaprine Hydrochloride Tablets USP, 7.5 mg are round, white, unscored, film-coated tablets debossed W52 on one side and TV on the other side and supplied as follows: Bottles of 1 NDC 76420-268-01 (repackaged from NDC 0093-3421-01) Bottles of 2 NDC 76420-268-02 (repackaged from NDC 0093-3421-01) Bottles of 7 NDC 76420-268-07 (repackaged from NDC 0093-3421-01) Bottles of 15 NDC 76420-268-15 (repackaged from NDC 0093-3421-01) Bottles of 20 NDC 76420-268-20 (repackaged from NDC 0093-3421-01) Bottles of 30 NDC 76420-268-30 (repackaged from NDC 0093-3421-01) Bottles of 60 NDC 76420-268-60 (repackaged from NDC 0093-3421-01) Bottles of 90 NDC 76420-268-90 (repackaged from NDC 0093-3421-01) Bottles of 100 NDC 76420-268-10 (relabeled from NDC 0093-3421-01) Cyclobenzaprine Hydrochloride Tablets USP, 10 mg are round, white, unscored, film-coated tablets debossed W53 on one side and TV on the other side and supplied as follows: Bottles of 1 NDC 76420-271-01 (repackaged from NDC 0093-3422-XX) Bottles of 2 NDC 76420-271-02 (repackaged from NDC 0093-3422-XX) Bottles of 7 NDC 76420-271-07 (repackaged from NDC 0093-3422-XX) Bottles of 15 NDC 76420-271-15 (repackaged from NDC 0093-3422-XX) Bottles of 20 NDC 76420-271-20 (repackaged from NDC 0093-3422-XX) Bottles of 30 NDC 76420-271-30 (repackaged from NDC 0093-3422-XX) Bottles of 60 NDC 76420-271-60 (repackaged from NDC 0093-3422-XX) Bottles of 90 NDC 76420-271-90 (repackaged from NDC 0093-3422-XX) Bottles of 100 NDC 76420-271-10 (relabeled/repackaged from NDC 0093-3422-01/0093-3422-XX) Bottles of 120 NDC 76420-271-12 (relabeled from NDC 0093-3422-XX) Dispense in a well-closed container with child-resistant closure. Store at 20° to 25°C (68° to 77°F) [see USP Controlled Room Temperature]. Relabeled and Repackaged by: Enovachem PHARMACEUTICALS Torrance, CA 90501