What is the recommended dose of Robaxin (methocarbamol) for a 15-year-old female weighing 105 pounds?

Methocarbamol (Robaxin) Dosing for a 15-Year-Old Female Weighing 105 Pounds

For a 15-year-old female weighing 105 pounds (approximately 47.6 kg), the recommended dose of methocarbamol (Robaxin) is 1500 mg three to four times daily.

Dosing Considerations

• For pediatric patients 15 years and older, adult dosing guidelines apply, as 15 years is considered the threshold for adult dosing in most medication protocols 1
• The standard adult dose of methocarbamol is 1500 mg four times daily for the first 48-72 hours, which may be reduced to 1000 mg four times daily for maintenance therapy 2, 3
• Weight-based dosing should be considered for adolescents who weigh less than adult average weight, with approximately 30-40 mg/kg/day divided into 3-4 doses being appropriate 1
• For this 15-year-old weighing 47.6 kg, the calculated dose would be approximately 1400-1900 mg per dose, which aligns with the standard adult dosing of 1500 mg 1, 3

Administration Guidelines

• Methocarbamol should be taken with food to minimize gastrointestinal side effects 3
• Initial treatment duration is typically 7-10 days, but should be discontinued once pain relief is achieved 3
• If symptoms persist beyond 7 days, reevaluation of the underlying condition is recommended 3

Safety Considerations

• Common side effects include drowsiness, dizziness, and lightheadedness; patient should be advised to avoid driving or operating machinery until effects are known 2, 3
• Methocarbamol has potential for CNS depression which can be potentiated by alcohol and other CNS depressants - these combinations should be strictly avoided 2
• Methocarbamol is generally well-tolerated in adolescents when used at appropriate doses 3
• No significant dose adjustments are needed for mild-to-moderate renal or hepatic impairment 3

Monitoring

• Monitor for relief of muscle spasm and associated pain 3
• Assess for improvement in mobility and function 3
• Watch for adverse effects, particularly excessive sedation or dizziness 2, 3
• If no improvement is seen within 3 days, consider alternative therapies or reassessment of diagnosis 3

Alternative Considerations

• If methocarbamol is not effective or not tolerated, consider non-pharmacological approaches such as physical therapy, heat application, or gentle stretching 3
• For acute low back pain with muscle spasm, methocarbamol has demonstrated superior efficacy compared to placebo in improving mobility and reducing pain 3