D-Glucose monohydrate

Absorption

Polysaccharides can be broken down into smaller units by pancreatic and intestinal glycosidases or intestinal flora. Sodium-dependent glucose transporter SGLT1 and GLUT2 (SLC2A2) play predominant roles in intestinal transport of glucose into the circulation. SGLT1 is located in the apical membrane of the intestinal wall while GLUT2 is located in the basolateral membrane, but it was proposed that GLUT2 can be recruited into the apical membrane after a high luminal glucose bolus allowing bulk absorption of glucose by facilitated diffusion . Oral preparation of glucose reaches the peak concentration within 40 minutes and the intravenous infusions display 100% bioavailability.

Toxicity

Oral LD50 value in rats is 25800mg/kg. The administration of glucose infusions can cause fluid and/or solute overloading resulting in dilution of the serum electrolyte concentrations, over-hydration, congested states, or pulmonary oedema. Hypersensitivity reactions may also occur including anaphylactic/anaphylactoid reactions from oral tablets and intravenous infusions.

The Uses of D-Glucose monohydrate

Replenisher (fluid and nutrient).

Indications

Glucose pharmaceutical formulations (oral tablets, injections) are indicated for caloric supply and carbohydrate supplementation in case of nutrient deprivation. It is also used in metabolic disorders such as hypoglycemia.

Background

Glucose is a simple sugar (monosaccharide) generated during phosynthesis involving water, carbon and sunlight in plants. It is produced in humans via hepatic gluconeogenesis and breakdown of polymeric glucose forms (glycogenolysis). It circulates in human circulation as blood glucose and acts as an essential energy source for many organisms through aerobic or anaerobic respiration and fermentation. It is primarily stored as starch in plants and glycogen in animals to be used in various metabolic processes in the cellular level. Its aldohexose stereoisomer, dextrose or D-glucose, is the most commonly occurring isomer of glucose in nature. L-glucose is a synthesized enantiomer that is used as a low-calorie sweetener and laxative. The unspecified form of glucose is commonly supplied as an injection for nutritional supplementation or metabolic disorders where glucose levels are improperly regulated. Glucose is listed on the World Health Organization's List of Essential Medicines.

Pharmacokinetics

Blood glucose is an obligatory energy source in humans involved in various cellular activities, and it also acts as a signalling molecule for diverse glucose-sensing molecules and proteins. Glucose undergoes oxidation into carbon dioxide, water and yields energy molecules in the process of glycolysis and subsequent citric cycle and oxidative phosphorylation. Glucose is readily converted into fat in the body which can be used as a source of energy as required. Under a similar conversion into storage of energy, glucose is stored in the liver and muscles as glycogen. Glucose stores are mobilized in a regulated manner, depending on the tissues' metabolic demands. Oral glucose tablets or injections serve to increase the supply of glucose and oral glucose administration is more effective in stimulating insulin secretion because it stimulates the incretin hormones from the gut, which promotes insulin secretion.

Metabolism

Glucose can undergo aerobic oxidation in conjunction to the synthesis of energy molecules. Glycolysis is the initial stage of glucose metabolism where one glucose molecule is degraded into 2 molecules of pyruvate via substrate-level phosphorylation. These products are transported to the mitochondria where they are further oxidized into oxygen and carbon dioxide.