Cyclobenzaprine hydrochloride 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, limitation of motion, and restriction in activities of daily living.Cyclobenzaprine hydrochloride 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 has not been found effective in the treatment of spasticity associated with cerebral or spinal cord disease, or in children with cerebral palsy.

---

Spasm -- An involuntary contraction of a muscle or group of muscles. Spasms may involve SKELETAL MUSCLE or SMOOTH MUSCLE.

Symptoms -- An indication that a person has a condition or disease. Some examples of symptoms are headache, fever, fatigue, nausea, vomiting, and pain.

Pain -- An unpleasant sensation induced by noxious stimuli which are detected by NERVE ENDINGS of NOCICEPTIVE NEURONS.

Sore to touch --

Muscle Spasticity -- A form of muscle hypertonia associated with upper MOTOR NEURON DISEASE. Resistance to passive stretch of a spastic muscle results in minimal initial resistance (a "free interval") followed by an incremental increase in muscle tone. Tone increases in proportion to the velocity of stretch. Spasticity is usually accompanied by HYPERREFLEXIA and variable degrees of MUSCLE WEAKNESS. (From Adams et al., Principles of Neurology, 6th ed, p54)

Spinal Cord Diseases -- Pathologic conditions which feature SPINAL CORD damage or dysfunction, including disorders involving the meninges and perimeningeal spaces surrounding the spinal cord. Traumatic injuries, vascular diseases, infections, and inflammatory/autoimmune processes may affect the spinal cord.

Cerebral Palsy -- A heterogeneous group of nonprogressive motor disorders caused by chronic brain injuries that originate in the prenatal period, perinatal period, or first few years of life. The four major subtypes are spastic, athetoid, ataxic, and mixed cerebral palsy, with spastic forms being the most common. The motor disorder may range from difficulties with fine motor control to severe spasticity (see MUSCLE SPASTICITY) in all limbs. Spastic diplegia (Little disease) is the most common subtype, and is characterized by spasticity that is more prominent in the legs than in the arms. Pathologically, this condition may be associated with LEUKOMALACIA, PERIVENTRICULAR. (From Dev Med Child Neurol 1998 Aug;40(8):520-7)

Hypersensitivity to any component of this product.Concomitant use of monoamine oxidase (MAO) inhibitors or within 14 days after their discontinuation.

Hyperpyretic crisis, severe convulsions, 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.

---

Hypersensitivity -- Altered reactivity to an antigen, which can result in pathologic reactions upon subsequent exposure to that particular antigen.

Convulsions -- the most dramatic type of seizure, characterized by tonic and clonic contraction of most skeletal muscles.

Myocardial Infarction -- NECROSIS of the MYOCARDIUM caused by an obstruction of the blood supply to the heart (CORONARY CIRCULATION).

cardiac arrhythmia -- any variation from the normal rhythm or rate of the heart beat.

Heart Block -- Impaired conduction of cardiac impulse that can occur anywhere along the conduction pathway, such as between the SINOATRIAL NODE and the right atrium (SA block) or between atria and ventricles (AV block). Heart blocks can be classified by the duration, frequency, or completeness of conduction block. Reversibility depends on the degree of structural or functional defects.

Abnormal cardiac conduction --

Congestive heart failure -- complication of heart diseases; defective cardiac filling and/or impaired contraction and emptying, resulting in the heart's inability to pump a sufficient amount of blood to meet the needs of the body tissues or to be able to do so only with an elevated filling pressure.

Hyperthyroidism -- Hypersecretion of THYROID HORMONES from the THYROID GLAND. Elevated levels of thyroid hormones increase BASAL METABOLIC RATE.

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, 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.

The following US Branded drugs contain Cyclobenzaprine hydrochloride

---

AMRIX -- ANESTA AG

FLEXERIL -- MCNEIL PEDIATRICS