DL-Methionine

(USAN)

💊 Chemical information

DL-Metionina; Methionin racemický; DL-Méthionine; DL-Methioninum; Methioninum Racemicum; no-4-(methylthio)butyric acid.
Chemical formula: C5H11NO2S = 149.2.
CAS — 59-51-8.
ATC — V03AB26.
ATC Vet — QV03AB26.

Pharmacopoeias.

In Eur., Int., and Viet.

Ph. Eur. 6.2

( DL-Methionine). An almost white crystalline powder or small flakes. Sparingly soluble in water; very slightly soluble in alcohol; dissolves in dilute acids and in dilute solutions of alkali hydroxides. A 2% solution in water has a pH of 5.4 to 6.1. Protect from light.

💊 Adverse Effects and Precautions

Methionine may cause nausea, vomiting, drowsiness, and irritability. It should not be used in patients with acidosis. Methionine may aggravate hepatic encephalopathy in patients with established liver damage; it should be used with caution in patients with severe liver disease.

💊 Interactions

Methionine may be adsorbed by activated charcoal and the effect of oral methionine may be reduced if they are given together.

Dopaminergics.

For reference to the antagonism of the antiparkinsonian effect of levodopa by methionine, see Nutritional Agents, under Interactions of Levodopa.

💊 Pharmacokinetics

Methionine is absorbed from the gastrointestinal tract. It is extensively metabolised to S-adenosylmethionine, homocysteine, and other metabolites, and is excreted in the urine as an inorganic sulfate.

💊 Uses and Administration

L-Methionine is an essential amino acid and is therefore included in amino-acid solutions used for parenteral nutrition. Methionine also enhances the synthesis of glutathione and is used as an alternative to acetylcysteine in the treatment of paracetamol poisoning to prevent hepatotoxicity. The literature relating to the use of methionine in paracetamol poisoning is, in general, imprecise as to the form of methionine used. In the UK, the usual dose of DL-methionine is 2.5 g by mouth every 4 hours for 4 doses starting less than 10 to 12 hours after ingestion of the paracetamol. Children under 6 years old may be given 1 g every 4 hours for 4 doses. Methionine has also been given intravenously. Preparations containing both methionine and paracetamol have been formulated for use in situations where overdosage may occur. However, the issue of whether methionine should be routinely added to paracetamol preparations is contentious for medical and ethical reasons. Methionine has also been given orally to lower urinary pH and as an adjunct in the treatment of liver disorders. It has also been used in the assessment of hyperhomocysteinaemia. Acetylmethionine has also been used.

💊 Preparations

Proprietary Preparations

Arg.: Neutrodor†; Austral.: Methnine; Austria: Acimethin; Ger.: Acimethin; Acimol; Methio; Methiotrans; Urol methin; Uromethin†; Switz.: Acimethin; USA: M-Caps; Pedameth†; Uracid. Multi-ingredient: Austral.: Berberis Complex; Liv-Detox†; Braz.: Aminotox†; Anekron; Betaliver†; Biohepax; Enterofigon; Epativan; Epocler; Extrato Hepatico Composto; Extrato Hepatico Vitaminado†; Hecrosine B12†; Hepacitron†; Hepalin; Hepatogenol†; Hepatotris†; Hepatox; Hormo Hepatico†; Lisotox; Metiocolin B12; Metiocolin Composto; Necro B-6; Panvitrop; Regenom; Silimalon; Xantina B12†; Xantinon B12; Xantinon Complex; Canad.: Amino-Cerv; Selenium Plus; Cz.: Lipovitan†; Fr.: Cysti-Z†; Lobamine-Cysteine; Nivabetol; Verrulyse-Methionine; Ger.: Lipovitan†; Hong Kong: Bilsan; Lipochol; India: Neutrosec; Indon.: BIO-EPL; Lipagent; Methicol; Methioson; Naturica DFM; Vionin NF; Irl.: Antox; Ital.: Agedin Plus; Detoxicon; Meziv†; Mex.: Lipovitasi-Or; S.Afr.: Hepavite; Spain: Dertrase; Epitelizante; Switz.: Mechovit; Thai.: Bio-Vitas†; Lipochol; Liporon; UK: Lipotropic Factors; Paradote; USA: Amino-Cerv.
Published November 24, 2018.