Home Drug Guide Methocarbamol

Drug Guide

Generic Name

Methocarbamol

Brand Names Robaxin, Robaxin-750, Forbaxin, Delaxin

Classification

Therapeutic: Muscle relaxant

Pharmacological: Central muscle relaxant

FDA Approved Indications

Relief of discomfort associated with acute, painful musculoskeletal conditions

Mechanism of Action

Methocarbamol acts centrally to produce sedative and muscle relaxant effects, likely through general depression of nerve transmission within the reticulospinal pathways in the brain.

Dosage and Administration

Adult: Typically, 1500 mg four times daily for 2-3 days, then 750 mg four times daily as needed. Tapering is not usually required.

Pediatric: Safety and efficacy not established; use in children is not generally recommended.

Geriatric: Use with caution; consider lower doses due to increased sensitivity and risk of side effects.

Renal Impairment: Adjust dosage based on severity of impairment; monitoring recommended.

Hepatic Impairment: Use with caution; no specific dosage adjustment established.

Pharmacokinetics

Absorption: Well absorbed from the gastrointestinal tract

Distribution: Distributed widely, crosses the blood-brain barrier

Metabolism: Minimal hepatic metabolism

Excretion: Primarily via the urine in unchanged form and conjugates

Half Life: Approximately 1-2 hours in healthy adults

Contraindications

Allergy to methocarbamol or any component of the formulation.
Severe renal impairment

Precautions

Use with caution in patients with hepatic impairment, renal impairment, or with a history of hypersensitivity reactions.
May cause drowsiness; caution in patients performing hazardous tasks.
Potential for drug interactions with central nervous system depressants.

Adverse Reactions - Common

Drowsiness (Common)
Dizziness (Common)
Lightheadedness (Common)
Gastrointestinal upset (nausea, vomiting) (Less common)

Adverse Reactions - Serious

Seizures (Rare)
Allergic reactions (rash, angioedema, anaphylaxis) (Rare)
Blood dyscrasias (e.g., leukopenia, anemia) (Very rare)

Drug-Drug Interactions

CNS depressants (e.g., opioids, benzodiazepines) may increase Sedation.
Potential additive effect with other muscle relaxants.

Drug-Food Interactions

N/A

Drug-Herb Interactions

N/A

Nursing Implications

Assessment: Monitor for effectiveness in relieving muscle spasm and pain; observe for side effects such as sedation or allergic reactions.

Diagnoses:

Ineffective airway clearance related to CNS depression.
Risk for injury related to dizziness or sedation.

Implementation: Administer with food or milk to minimize gastrointestinal upset. Assess for allergic reactions and sedation periodically.

Evaluation: Assess relief of muscle spasm and pain, monitor for adverse effects.

Patient/Family Teaching

Do not operate machinery or drive until response is known.
Avoid alcohol and other CNS depressants.
Report excessive drowsiness, rash, or difficulty breathing.
Take medication exactly as prescribed.

Special Considerations

Black Box Warnings: N/A

Genetic Factors: None specific.

Lab Test Interference: None reported.

Overdose Management

Signs/Symptoms: Drowsiness, vomiting, hypotension, possible coma.

Treatment: Supportive care, maintain airway and breathing, activated charcoal if ingestion is recent, seizure control if necessary, no specific antidote.

Storage and Handling

Storage: Store at room temperature, away from moisture, heat, and light.

Stability: Stable under recommended conditions.