GVSOFT 1.2

Indications

• Constipation
• Decreased intraocular pressure

Dosage

Children: For children, refer to the BNF for Children for appropriate glycerin dosing guidelines.

Adults: For constipation, glycerin can be administered rectally as a suppository. Follow specific product guidelines for dosage.

Mechanism of action

When administered rectally, glycerine exerts a hygroscopic and/or local irritant action, drawing water from the tissues into the feces and reflexively stimulating evacuation. Additionally, glycerine decreases intraocular pressure by creating an osmotic gradient between the blood and intraocular fluid, leading to fluid movement out of the aqueous and vitreous humors into the bloodstream.

Pharmacodynamics

Glycerine is commonly classified as an osmotic laxative but may also exert local irritant effects, lubricating, and fecal softening actions. Its onset of action typically occurs within 15 to 30 minutes when used as a suppository.

Pharmacokinetics

Glycerine is readily absorbed and metabolized in the body. It undergoes glycerol metabolism pathways, contributing to various biochemical processes including phospholipid biosynthesis. The pharmacokinetic profile of glycerine indicates a rapid onset of action due to its osmotic properties.

Adverse effects

• Abdominal cramps
• Diarrhea
• Nausea
• Vomiting
• Electrolyte imbalance

Precautions

• Use with caution in patients with renal impairment
• May cause dehydration if used excessively
• Monitor for electrolyte disturbances in prolonged use

Pregnancy

Glycerin is generally considered safe to use during pregnancy for indicated conditions. Always consult a healthcare provider before use.

Breast-feeding

Glycerin is unlikely to be harmful in breastfeeding mothers. Consult a healthcare provider for specific guidance.

Storage

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

Formulations

• Suppositories
• Oral solution

Mechanism of action

When administered rectally, glycerin exerts a hygroscopic and/or local irritant action, drawing water from the tissues into the feces and reflexively stimulating evacuation. Glycerin decreases intraocular pressure by creating an osmotic gradient between the blood and intraocular fluid, causing fluid to move out of the aqueous and vitreous humors into the bloodstream. Glycerin (glycerol) and sorbitol are hyperosmotic laxatives. When administered rectally, glycerin and sorbitol exert a hygroscopic and/or local irritant action, drawing water from the tissues into the feces and reflexly stimulating evacuation. The extent to which the simple physical distention of the rectum and the hygroscopic and/or local irritant actions are responsible for the laxative effects of some of these drugs is not known. Only extremely high oral doses of sorbitol (25 g daily) or glycerin exert laxative action. /Glycerin/ decreases intraocular pressure by creating an osmotic gradient between the blood and intraocular fluid, causing fluid to move out of the aqueous and vitreous humors into the bloodstream. The physicochemical effects of a series of alkanols, alkanediols and glycerol on erythrocyte shape and hemolysis at 4 and 20 degrees C were examined. We calculated the dielectric constant of the incubation medium, Ds, and the dielectric constant of the erythrocyte membrane Dm in the presence of organic solutes. The ratio Ds/Dm = -38.48 at 20 degrees C defines the normal biconcave shape in a medium without hemolytic agents. A decrease in Ds/Dm favors externalization or internalization with consequent hemolysis. Alkanols and alkanediols convert biconcave erythrocytes into echinocytes, which is accompanied by an increase in the projected surface area. Glycerol converts biconcave erythrocytes into stomatocytes, which was accompanied by a marginal decrease in the projected surface area. Progressive externalization in alkanols and alkanediols or internalization in glycerol resulted in a decrease in the projected surface area and the formation of smooth spheres. The degree of shape change induced was related to the degree of hemolysis and the ratio Ds/Dm. A decrease in temperature reduced both the degree of shape change and hemolysis. .../Thus/ physicochemical toxicity may be a result of a temperature dependent hydrophobic interaction between the organic solutes and the membrane and is best interpreted by the ability of the solutes to change Ds and Dm.

Pharmacodynamics

Glycerin is commonly classified as an osmotic laxative but may act additionally or alternatively through its local irritant effects; it may also have lubricating and fecal softening actions. Glycerin suppositories usually work within 15 to 30 minutes.