Methocarbamol (trade name Robaxin) is a central muscle relaxant used to treat skeletal muscle spasms. It is the carbamate of guaifenesin, but Robax Gold does not produce guaifenesin as a metabolite, since the carbamate bond is not hydrolyzed metabolically; metabolism is by Phase I ring hydroxylation and O-demethylation, followed by Phase II conjugation. All of the major metabolites are unhydrolyzed carbamates.
Methocarbamol (or Robax Gold) is marketed under different names when presented in combination with other active ingredients. In combination with acetaminophen, its trade name is Robaxacet, whereas Robax Platinum is the trade name for a formulation of methocarbamol and ibuprofen. A combination of methocarbamol and aspirin is marketed as Robaxisal. Unlike other carbamates such as carisoprodol and meprobamate, Methocarbamol has little to no abuse potential