Metabolism
Methocarbamol is the carbamate derivative of guaifenesin, but does not produce guaifenesin as a metabolite, because the carbamate bond is not hydrolyzed metabolically; its metabolism is by Phase I ring hydroxylation and O-demethylation, followed by Phase II conjugation. All the major metabolites are unhydrolyzed carbamates. Small amounts of unchanged methocarbamol are also excreted in the urine. Society and culture
Methocarbamol was approved as a muscle relaxant for acute, painful musculoskeletal conditions in the United States in 1957. Muscle relaxants are widely used to treat low back pain, one of the most frequent health problems in industrialized countries. Currently, there are more than 3 million prescriptions filled yearly. Methocarbamol and orphenadrine are each used in more than 250,000 U.S. emergency department visits for lower back pain each year. In the United States, low back pain is the fifth most common reason for all physician visits and the second most common symptomatic reason. In 80% of primary care visits for low back pain, at least one medication was prescribed at the initial office visit and more than one third were prescribed two or more medications. The most commonly prescribed drugs for low back pain included skeletal muscle relaxants. Cyclobenzaprine and methocarbamol are on the U.S. Medicare formulary, which may account for the higher use of these products. Economics
The generic formulation of the medication is relatively inexpensive, costing less than the alternative metaxalone in 2016.
Although the sample size of the studies performed are small due to the rarity of the disease, the findings are indicative of a correlation between the disease and several specific protein biomarkers. Other studies have confirmed the correlation of moyamoya and adhesion molecule 1 (ICAM-1) being increased as compared to normal vascular function counterparts. Furthermore, it has been concluded that the localization of inflammatory cells suggests that the inflammation stimulus itself may be responsible for the proliferation and occlusion in the ICA, ACA, and MCA found in those with moyamoya disease. Treatment
Drugs such as antiplatelet agents (including aspirin) are usually given to prevent clots, but surgery is usually recommended. Because moyamoya tends to affect only the internal carotid artery and nearby sections of the adjacent anterior and middle cerebral arteries, surgeons can direct other arteries, such as the external carotid artery or the superficial temporal artery to replace its circulation. The arteries are either sewn directly into the brain circulation, or placed on the surface of the brain to reestablish new circulation after a few weeks.There are many operations that have been developed for the condition, but currently the most favored are the in-direct procedures EDAS, EMS, and multiple burr holes and the direct procedure STA-MCA. Combined revascularisation procedure, which includes both the direct superficial temporal artery (STA) to middle cerebral artery (MCA) bypass performed with a combination of in-direct procedures, is considered the treatment of choice.