From the FDA Drug Label
DOSAGE AND ADMINISTRATION Methocarbamol, 500 mg — Adults: Initial dosage: 3 tablets q.i.d. Maintenance dosage: 2 tablets q.i.d. Methocarbamol, 750 mg — Adults: Initial dosage: 2 tablets q.i.d. Maintenance dosage: 1 tablet q.4h. or 2 tablets t.i.d. Six grams a day are recommended for the first 48 to 72 hours of treatment. (For severe conditions 8 grams a day may be administered). Thereafter, the dosage can usually be reduced to approximately 4 grams a day. The maximum recommended dose of Robaxin (methocarbamol) is 8 grams a day for the first 48 to 72 hours of treatment for severe conditions 1.
From the Research
The maximum recommended dose of Robaxin (methocarbamol) is 8 grams per day for adults. Typically, the initial dosing regimen is 1500 mg four times daily for the first 48-72 hours of acute musculoskeletal pain or spasm, followed by a maintenance dose of 750 mg every 4 hours or 1000 mg four times daily. Individual doses should not exceed 1500 mg at one time. This medication works as a central-acting muscle relaxant that helps relieve pain and discomfort caused by muscle sprains, strains, or other injuries. Methocarbamol does not directly relax skeletal muscles but appears to reduce pain by depressing the central nervous system. Patients should be aware that this medication may cause drowsiness and impair their ability to drive or operate machinery. It's also important to take Robaxin with food if stomach upset occurs and to avoid alcohol while using this medication as it can increase drowsiness and dizziness. Elderly patients or those with liver or kidney impairment may require lower doses.
Some studies have investigated the efficacy and safety of methocarbamol in comparison to other muscle relaxants, such as baclofen, metaxalone, and tizanidine 2, 3, 4. However, these studies do not provide specific guidance on the maximum recommended dose of methocarbamol. A recent commentary discussed the potential toxicity of polyethylene glycol, an excipient in intravenous methocarbamol, but this does not affect the recommended dose of oral methocarbamol 5.
Key points to consider when prescribing Robaxin include:
- Initial dose: 1500 mg four times daily for the first 48-72 hours
- Maintenance dose: 750 mg every 4 hours or 1000 mg four times daily
- Maximum daily dose: 8 grams
- Individual doses should not exceed 1500 mg at one time
- Potential side effects: drowsiness, impaired driving or operating machinery, stomach upset
- Special considerations: elderly patients, liver or kidney impairment, avoidance of alcohol.