Description and Composition
This drug contains Methocarbamol as its active pharmaceutical ingredient and other inactive pharmaceutical ingredients called excipients. Methocarbamol comes in different dosage forms including tablets, solution for injection and suspension.
Uses and Indications
Methocarbamol is indicated as an adjunctive therapy for the relief of discomfort associated with acute painful musculoskeletal conditions. Methocarbamol is also indicated for control of muscle spasm in tetanus
Dosage and Administration
For Oral use in adult
Initial: 1.5gm taken qds or 4 times daily
Maintenance: 1 gm qds or 4 times daily.
For the first 48 to 72 hours, 6 gm per day is recommended.
For severe conditions, 8 g daily in divided doses may be administered and thereafter reduced to approximately 4 g or as directed by physician
Usage in Tetanus
Methocarbamol does not replace the usual procedure of tracheotomy, debridement, tetanus antitoxin, penicillin etc used in the treatment of tetanus. Rather, methocarbamol injection is added to this regimen.
Pharmacology and Mechanism of Action
Methocarbamol is a centrally acting skeletal muscle relaxant. Its mechanism of action has not been established, but may be due to general CNS depression. The drug has no direct action on the contractile mechanism of striated muscle, motor endplate or nerve fiber, it does not directly relax tensed skeletal muscles.
Methocarbamol is rapidly absorbed from the gastrointestinal tract following oral administration. Methocarbamol has an onset of action of 30 minutes. Peak plasma levels occur approximately 2 hours after administration of 2 gm. The half life is from 1 to 2 hours. Methocarbamol is metabolized, probably in the liver and excreted in urine primarily as the glucuronide and sulphate conjugates of its metabolites. A Small amount is excreted in faeces.
Some side effects associated with the use of methocarbamol include the following
- Rash conjunctivitis with nasal congestion
- Blurred vision
Precautions, Warnings and Use during Pregnancy
- Methocarbamol may impair concentration, patients so affected should not drive or operate machinery
- Methocarbamol is not recommended during pregnancy, especially during early pregnancy or in women who may become pregnant, unless potential benefits outweigh potential hazards.
- It is not known whether methocarbamol is excreted in breast milk. Exercise caution when administering to nursing women.
- Safety and efficacy of methocarbamol in children below 12 yrs. Old has not been established, except
Overdosage and its Treatment
Overdosage often is conjunction with alcohol or other CNS depressants, is marked by coma and other signs of CNS depression.
Treatment is essentially supportive. Simple isolated seizures may require only observation and supportive care. Repetitive seizures or status epilepticus require therapy. Diazepam iv. is generally the agent of choice, parenteral barbiturates have also been used.
Methocarbamol is contraindicated in hypersensitive patients, in coma or pre-coma states, brain damage, myasthenia gravis or in patients with a history of epilepsy.
Methocarbamol Drug Interactions
The CNS effects of methocarbamol may be potentiated by concomitant administration of other CNS depressants such as alcohol. Methocarbamol has also been stated to potentiated the effects of anorectics, antimuscarinics and some psychotropic agents.
Methocarbamol may cause a colour interference in certain screening tests for 5 hydroxy indole acetic acid (5-HIAA) and vanillylmandelic acid(VMA).
Storage of Methocarbamol
Store in a cool place below 25 C Protect from light. Keep out of reach of children.