Myonil50 mg

Myonil is a centrally-acting skeletal muscle relaxant used for the symptomatic relief of muscle spasm, spasticity, and stiffness associated with a range of musculoskeletal and neurological conditions. Its use is supported by clinical experience and regulatory approval in several countries, though it is not FDA-approved in the United States.

• Established uses:
  • Relief of muscle spasm/tension associated with cervical spondylosis, lumbar spondylosis, and periarthritis of the shoulder (frozen shoulder/shoulder-arm-neck syndrome)
  • Low back pain (lumbago) with associated muscle spasm
  • Spastic paralysis due to cerebrovascular disease, cervical spondylotic myelopathy, and sequelae of spinal cord injury or head trauma
• Guideline-supported/adjunct uses: Used as an adjunct to physiotherapy, rest, and analgesics in the overall management of painful musculoskeletal spasm; also used as an adjunct in spasticity associated with neurodegenerative conditions such as amyotrophic lateral sclerosis (ALS), cerebral palsy, and spinocerebellar degeneration, alongside condition-specific therapy.
• Not a substitute for underlying treatment: Myonil relieves the muscular symptom but does not treat the underlying neurological or structural cause; a physician should evaluate and manage the primary condition.

Each tablet contains Eperisone Hydrochloride as the active ingredient, most commonly available as:

• Eperisone Hydrochloride 50 mg tablet

Tablets also contain standard pharmaceutical excipients (fillers, binders, disintegrants, and coating agents); refer to the specific product label for the complete excipient list, particularly in patients with known excipient sensitivities.

Myonil is a centrally-acting skeletal muscle relaxant belonging to the pyrrolidine chemical class. It is used orally for the symptomatic treatment of muscle spasticity and painful muscle spasm arising from musculoskeletal and certain neurological disorders.

Unlike benzodiazepine-type muscle relaxants, Myonil acts through a dual mechanism involving both the central nervous system and the peripheral vasculature, and is generally associated with a lower incidence of pronounced sedation, although drowsiness can still occur (see Precautions and Warnings).

Skeletal Muscle Relaxant (Centrally-Acting Antispasmodic)

Eperisone Hydrochloride is a centrally-acting muscle relaxant that reduces excessive muscle tone and spasm through actions at both the spinal and vascular level.

• It suppresses the excitability of spinal polysynaptic reflexes and reduces the sensitivity of muscle spindles by acting on gamma motor neuron pathways in the spinal cord, thereby reducing excessive muscle tone.
• It also has a mild direct vasodilatory effect on vascular smooth muscle, which improves intramuscular blood flow and may contribute to a secondary analgesic effect by reducing local ischemia and pain associated with sustained muscle spasm.
• Peak plasma concentration is typically reached within 1-2 hours of oral administration, and the drug is extensively metabolized in the liver before renal excretion.

The following clinically significant interactions have been reported with Myonil:

• CNS depressants (alcohol, benzodiazepines, other sedatives/muscle relaxants): Concurrent use may cause additive central nervous system depression, increasing drowsiness, dizziness, and the risk of falls; concurrent use should be avoided or closely monitored.
• Antihypertensive agents: Because Myonil has mild vasodilatory activity, it may potentiate the blood-pressure-lowering effect of antihypertensive drugs; blood pressure should be monitored when co-administered.
• Other drugs causing muscle weakness: Concomitant use with other agents known to cause muscle weakness may increase the risk or severity of this effect.

Side effects reported with Myonil are generally mild, but rare serious reactions can occur.

Patients should seek prompt medical attention if signs of a serious allergic reaction, unusual bruising/bleeding, or marked muscle weakness occur.

The safety of Myonil in pregnancy has not been well established in controlled human studies. It should be used during pregnancy only if clearly needed and if the potential benefit justifies the potential risk to the fetus; a physician should be consulted before use.

It is not known whether Myonil is excreted in human breast milk. As a precaution, use during breastfeeding should be avoided unless a physician determines that the benefit to the mother outweighs any potential risk to the nursing infant.

The following precautions apply to the use of Myonil:

• Hepatic/renal impairment: Use with caution and under close medical supervision, as the drug is hepatically metabolized and impairment may alter clearance.
• Elderly patients: Increased sensitivity to sedative effects and higher fall risk; a reduced dose with close monitoring is recommended.
• Drowsiness/dizziness: Myonil may impair mental alertness or physical coordination; patients should avoid driving or operating heavy machinery until they know how the drug affects them.
• Hypersensitivity/anaphylactoid reactions: Rare but severe hypersensitivity and anaphylactoid reactions have been reported, sometimes with initial doses; patients should be monitored, especially early in treatment, and the drug discontinued immediately if such reactions occur.
• Muscle weakness: Myonil can occasionally cause or worsen muscle weakness; the lowest effective dose should be used, particularly in patients with pre-existing muscle weakness or neuromuscular disease.

Overdose with Myonil may cause pronounced central nervous system depression, muscle weakness, hypotension, and, particularly in infants and young children, seizures. There is no specific antidote.

Any suspected overdose is a medical emergency: seek immediate medical attention or contact emergency services/a poison control center. Management is supportive and symptomatic, guided by a physician in a monitored setting; do not attempt specific home treatment.

Store at room temperature (below 30°C), away from light and moisture. Keep out of reach of children.

Elderly: Patients should generally start at a reduced dose of Myonil with close monitoring, given increased susceptibility to sedation, dizziness, and fall risk.

Pediatric patients: Safety and efficacy of Myonil in children have not been established; its use in this population is not recommended (see Pediatric Uses).

Hepatic/renal impairment: Use with caution and closer clinical monitoring, as described in Precautions and Warnings.

The duration of treatment with Myonil should be individualized by the prescribing physician based on the underlying condition and response to therapy. For acute musculoskeletal muscle spasm, short courses of days to a few weeks are typical alongside physiotherapy and rest, while chronic spastic conditions may require longer-term use with periodic reassessment of continued need and effectiveness.

Centrally-acting skeletal muscle relaxants; Antispasmodics

Eperisone Hydrochloride acts centrally to suppress spinal polysynaptic reflexes and reduce muscle spindle sensitivity via effects on gamma motor neuron pathways, thereby lowering excessive skeletal muscle tone. It also produces mild peripheral vasodilation, improving intramuscular blood flow, which may add a secondary analgesic benefit in painful muscle spasm.

The safety and efficacy of Myonil in children have not been established. Its use in the pediatric population is generally not recommended, and it should only be considered if specifically directed by a pediatric specialist after weighing potential risks and benefits.