According to Drugs.com, pill imprint 4212 V identifies the 750-milligram dosage of methocarbamol. This drug belongs to the class of skeletal muscle relaxants and is most commonly used to treat muscle spasms. It is also used in the treatment of opiate withdrawal.
According to the National Institutes of Health, methocarbamol is used in conjunction with rest and physical therapy to relieve muscular pain and discomfort associated with muscle sprains, spasms and other types of muscle injuries. It works by slowing down activity within a patient's nervous system so that his body relaxes throughout his recovery from his illness or injury.
This medicine is usually prescribed to be taken three or four times per day, with or without food. However, WebMD does list several side effects of methocarbamol that must be noted by patients before and during their use of the drug. These side effects include stomach upset, dizziness, drowsiness and blurred vision. More serious side effects of this drug include fainting, yellowing of the eyes or skin, breathing difficulties, skin rashes, and swelling or itching of the face or throat.
WebMD also warns that patients who take other drugs which cause drowsiness, such as diazepam, codeine or diphenhydramine, must alert their doctors to the dosage and frequency of these medications to avoid a potentially life-threatening drug interaction.