Methyl is an organic radical whose chemical formula is CH3, and which forms the centre of a wide group of substances known as the methyl group. For example, methyl alcohol is obtained as a by-product in the manufacture of beet-sugar, or by distillation of wood; methyl salicylate is the active constituent in oil of wintergreen; methyl hydride is better known as marsh gas.
Methyl alcohol, or wood spirit (see METHANOL), is distilled from wood and is thus a cheap form of alcohol. It has actions similar to, but much more toxic than, those of ethyl alcohol. It has a specially pronounced action on the nervous system, and in large doses is apt to cause neuritis, especially of the optic nerves, leading to blindness, partial or complete.
A drug that stimulates the CENTRAL NERVOUS SYSTEM. Its action is similar to DEXAMPHETAMINE. A controlled drug, one of its trade names is Ritalin® and it is (controversially) used in the treatment of ATTENTION DEFICIT DISORDER (HYPERACTIVITY SYNDROME) in children, in conjunction with behavioural treatment and family support. Because of the potential for side-effects, its administration should be under specialist supervision.... methylphenidate
Also called oil of Wintergreen, the liquid has analgesic (see ANALGESICS) and counter-irritant properties. Rubbed into the skin, the oil helps to relieve pain in LUMBAGO, SCIATICA and ‘rheumatic conditions’.... methyl salicylate
Methylene blue, or methylthionin chloride, is used in a dose of 75–100 mg, as a 1-per-cent intravenous injection, in the treatment of METHAEMOGLOBINAEMIA, which may occur following high doses of local anaesthetics such as prilocaine.... methylene blue
a mixture consisting mainly of ethyl alcohol with *methyl alcohol and petroleum hydrocarbons. The addition of pyridine gives it an objectionable smell, and the dye methyl violet is added to make it recognizable as unfit to drink. It is used as a solvent, cleaning fluid, and fuel.... methylated spirits
n. a preservative chemical commonly used in water-based products, such as cosmetics and toiletries. It is responsible for an epidemic of allergic contact *dermatitis, with intermittent facial dermatitis being the commonest presentation.... methylisothiazolinone
(methylmalonic acidaemia, aminoacidopathy) a defect of amino acid metabolism causing an excess of methylmalonic acid in the urine and blood. There are two types: one is an *inborn error of metabolism due to a deficiency of the enzyme methylmalonyl-CoA mutase; the other is an acquired type due to deficiency of vitamin B12, which results in defective synthesis of adenosylcobalamin (a cofactor in this metabolic process).... methylmalonic aciduria
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