METIOSITOL SOLUTION

Indications

• Primary carnitine deficiency
• Secondary carnitine deficiency (e.g., due to certain metabolic disorders)
• Certain conditions associated with impaired fatty acid oxidation
• Supportive treatment in patients with heart disease or metabolic syndrome

Dosage

Children: Refer to BNF for Children for specific dosing recommendations based on the child's condition and age.

Adults: Refer to BNF for specific dosing recommendations based on the condition being treated.

Mechanism of action

Carnitine facilitates the transport of long-chain fatty acids across the mitochondrial membrane by forming acyl-carnitine derivatives. This process is essential for the β-oxidation of fatty acids, enabling their conversion into acetyl-CoA, which enters the citric acid cycle to produce ATP. Additionally, carnitine plays a role in the removal of toxic acyl groups from the mitochondria, thus helping to detoxify the cell.

Pharmacodynamics

Carnitine enhances fatty acid oxidation and energy production in tissues that rely heavily on fat as a fuel source. It helps maintain cellular energy homeostasis, supports metabolic functions, and may have protective effects against oxidative stress by improving mitochondrial function.

Pharmacokinetics

Carnitine is absorbed in the gastrointestinal tract, with peak plasma concentrations typically occurring within 3-5 hours post-ingestion. It is distributed widely in body tissues, with high concentrations found in skeletal and cardiac muscle. Carnitine is primarily excreted in the urine as free carnitine and acyl-carnitine derivatives. The half-life of carnitine in plasma is approximately 2-3 hours, and its levels can be influenced by dietary intake and renal function.

Adverse effects

• Nausea
• Vomiting
• Abdominal cramps
• Diarrhea
• Fishy body odor

Precautions

• Use with caution in patients with renal impairment
• Monitor for changes in renal function

Pregnancy

Safety in pregnancy has not been established.

Breast-feeding

Carnitine is excreted in breast milk; use caution.

Storage

Store in a cool, dry place, protected from light.

Formulations

• Carnitine oral solution
• Carnitine tablets

Indications

• Choline deficiency
• Support in liver function
• Neurological health, including cognitive function
• Fat metabolism disorders

Dosage

Children: Refer to the BNF for Children for specific dosing guidelines.

Adults: Refer to the BNF for specific dosing guidelines.

Mechanism of action

Choline is a major component of phosphatidylcholine, which is essential for maintaining cell membrane integrity, facilitating information flow, and intracellular communication. It is involved in the synthesis of acetylcholine, a key neurotransmitter in the central nervous system. Choline deficiency can lead to apoptosis by affecting cell membrane composition and increasing ceramide levels, which activates apoptotic pathways. Additionally, choline is a precursor to betaine, which helps regulate homocysteine levels, thus reducing cardiovascular risks.

Pharmacodynamics

Choline is crucial for proper nerve conduction in the central nervous system as it is a precursor for acetylcholine. It supports liver function, gallbladder regulation, and lipid metabolism. Adequate choline levels are associated with the prevention of excessive fat accumulation in the liver and may mitigate conditions such as Parkinsonism and tardive dyskinesia. Deficiencies can lead to serious health problems, including liver dysfunction and stunted growth.

Pharmacokinetics

Choline is absorbed in the intestines and distributed throughout the body, where it is utilized in various metabolic pathways. The liver plays a central role in choline metabolism, converting it into phosphatidylcholine and other metabolites. The half-life and excretion pathways of choline are not well defined but are influenced by dietary intake, physiological state, and individual metabolism.

Interactions

• corticosteroids+cholinesalicylate: Unknown (decreases concentration)

Pregnancy

Choline is generally considered safe during pregnancy, as it is essential for fetal development, particularly for brain development and function. However, it is important to adhere to recommended dietary allowances.

Breast-feeding

Choline is important during breastfeeding as it supports infant brain development. Adequate intake is recommended for nursing mothers.

Storage

Store in a cool, dry place, away from direct sunlight and moisture. Keep out of reach of children.

Indications

• Methionine deficiency
• Hepatotoxicity prevention
• Cholesterol management

Mechanism of action

The mechanism of the possible anti-hepatotoxic activity of L-methionine is not entirely clear. It is thought that metabolism of high doses of acetaminophen in the liver leads to decreased levels of hepatic glutathione and increased oxidative stress. L-methionine serves as a precursor to L-cysteine, which has antioxidant properties and is a precursor to glutathione. The antioxidant activity of L-methionine and its metabolites likely contribute to its potential anti-hepatotoxic effects. Methionine also exhibits free-radical scavenging activity and chelating ability due to its sulfur content.

Pharmacodynamics

L-Methionine functions as a primary supplier of sulfur, which is essential for preventing hair, skin, and nail disorders. It aids in lowering cholesterol levels by enhancing the liver's production of lecithin, reducing liver fat, and protecting kidney function. Methionine acts as a natural chelating agent for heavy metals and helps regulate ammonia formation, contributing to ammonia-free urine and reduced bladder irritation. Furthermore, it influences hair follicles and promotes hair growth, in addition to its potential protective effects against hepatotoxins like acetaminophen.

Pharmacokinetics

Methionine is absorbed from the gastrointestinal tract and is distributed throughout the body, where it is utilized in protein synthesis and converted into other metabolites, such as S-adenosylmethionine and L-cysteine. The metabolism of methionine involves several pathways, including transsulfuration to cysteine and incorporation into proteins. The renal clearance of methionine is significant, as it is involved in the regulation of nitrogen balance and the formation of ammonia.

Adverse effects

• Nausea
• Vomiting
• Abdominal pain
• Allergic reactions

Precautions

• Use with caution in patients with liver disease
• Monitor for allergic reactions in sensitive individuals

Pregnancy

There is insufficient evidence to determine the safety of methionine during pregnancy. Consult a healthcare provider before use.

Breast-feeding

It is not known whether methionine is excreted in human milk. Caution is advised when administering to breastfeeding women.

Storage

Store in a cool, dry place away from direct sunlight. Keep out of reach of children.

Formulations

• Oral tablets
• Powder for oral solution

Mechanism of action

Choline is a major part of the polar head group of phosphatidylcholine. Phosphatidylcholine's role in the maintenance of cell membrane integrity is vital to all of the basic biological processes: information flow, intracellular communication and bioenergetics. Inadequate choline intake would negatively affect all these processes. Choline is also a major part of another membrane phospholipid, sphingomyelin, also important for the maintenance of cell structure and function. It is noteworthy and not surprising that choline deficiency in cell culture causes apoptosis or programmed cell death. This appears to be due to abnormalities in cell membrane phosphatidylcholine content and an increase in ceramide, a precursor, as well as a metabolite, of sphingomyelin. Ceramide accumulation, which is caused by choline deficiency, appears to activate Caspase, a type of enzyme that mediates apoptosis. Betaine or trimethylglycine is derived from choline via an oxidation reaction. Betaine is one of the factors that maintains low levels of homocysteine by resynthesizing L-methionine from homocysteine. Elevated homocysteine levels are a significant risk factor for atherosclerosis, as well as other cardiovascular and neurological disorders. Acetylcholine is one of the major neurotransmitters and requires choline for its synthesis. Adequate acetylcholine levels in the brain are believed to be protective against certain types of dementia, including Alzheimer's disease.

Pharmacodynamics

This compound is needed for good nerve conduction throughout the CNS (central nervous system) as it is a precursor to acetylcholine (ACh). Choline is also needed for gallbladder regulation, liver function and lecithin (a key lipid) formation. Choline also aids in fat and cholesterol metabolism and prevents excessive fat build up in the liver. Choline has been used to mitigate the effects of Parkinsonism and tardive dyskinesia. Choline deficiencies may result in excessive build-up of fat in the liver, high blood pressure, gastric ulcers, kidney and liver dysfunction and stunted growth.

Mechanism of action

The mechanism of the possible anti-hepatotoxic activity of L-methionine is not entirely clear. It is thought that metabolism of high doses of acetaminophen in the liver lead to decreased levels of hepatic glutathione and increased oxidative stress. L-methionine is a precursor to L-cysteine. L-cysteine itself may have antioxidant activity. L-cysteine is also a precursor to the antioxidant glutathione. Antioxidant activity of L-methionine and metabolites of L-methionine appear to account for its possible anti-hepatotoxic activity. Recent research suggests that methionine itself has free-radical scavenging activity by virtue of its sulfur, as well as its chelating ability. Amino acids are selected for protein synthesis by binding with transfer RNA (tRNA) in the cell cytoplasm. The information on the amino acid sequence of each individual protein is contained in the sequence of nucleotides in the messenger RNA (mRNA) molecules, which are synthesized in the nucleus from regions of DNA by the process of transcription. The mRNA molecules then interact with various tRNA molecules attached to specific amino acids in the cytoplasm to synthesize the specific protein by linking together individual amino acids; this process, known as translation, is regulated by amino acids (e.g., leucine), and hormones. Which specific proteins are expressed in any particular cell and the relative rates at which the different cellular proteins are synthesized, are determined by the relative abundances of the different mRNAs and the availability of specific tRNA-amino acid combinations, and hence by the rate of transcription and the stability of the messages. From a nutritional and metabolic point of view, it is important to recognize that protein synthesis is a continuing process that takes place in most cells of the body. In a steady state, when neither net growth nor protein loss is occurring, protein synthesis is balanced by an equal amount of protein degradation. The major consequence of inadequate protein intakes, or diets low or lacking in specific indispensable amino acids relative to other amino acids (often termed limiting amino acids), is a shift in this balance so that rates of synthesis of some body proteins decrease while protein degradation continues, thus providing an endogenous source of those amino acids most in need. /Protein synthesis/ The mechanism of intracellular protein degradation, by which protein is hydrolyzed to free amino acids, is more complex and is not as well characterized at the mechanistic level as that of synthesis. A wide variety of different enzymes that are capable of splitting peptide bonds are present in cells. However, the bulk of cellular proteolysis seems to be shared between two multienzyme systems: the lysosomal and proteasomal systems. The lysosome is a membrane-enclosed vesicle inside the cell that contains a variety of proteolytic enzymes and operates mostly at acid pH. Volumes of the cytoplasm are engulfed (autophagy) and are then subjected to the action of the protease enzymes at high concentration. This system is thought to be relatively unselective in most cases, although it can also degrade specific intracellular proteins. The system is highly regulated by hormones such as insulin and glucocorticoids, and by amino acids. The second system is the ATP-dependent ubiquitin-proteasome system, which is present in the cytoplasm. The first step is to join molecules of ubiquitin, a basic 76-amino acid peptide, to lysine residues in the target protein. Several enzymes are involved in this process, which selectively targets proteins for degradation by a second component, the proteasome. /Protein degradation/ Methionine dependence, the inability of cells to grow when the amino acid methionine is replaced in culture medium by its metabolic precursor homocysteine, is characteristic of many cancer cell lines and some tumors in situ. Most cell lines proliferate normally under these conditions. The methionine dependent t

Pharmacodynamics

L-Methionine is a principle supplier of sulfur which prevents disorders of the hair, skin and nails; helps lower cholesterol levels by increasing the liver's production of lecithin; reduces liver fat and protects the kidneys; a natural chelating agent for heavy metals; regulates the formation of ammonia and creates ammonia-free urine which reduces bladder irritation; influences hair follicles and promotes hair growth. L-methionine may protect against the toxic effects of hepatotoxins, such as acetaminophen. Methionine may have antioxidant activity.