Mannite, better known as D-mannitol, is a sugar, a monosaccharide long known for its laxative virtues. Belonging to the category of polyols, mannitol can be industrially synthesized starting from sucrose, while the natural source of mannite par excellence is represented by manna; it is a sugar secretion that naturally flows from the stem of the ash ( Fraxinus ornus L.) following incisions made by humans or the bites of some insects.
Mannitis as a laxative: doses and methods of use
Being an unabsorbable sugar, mannite acts as a perfect osmotic laxative, drawing water into the intestinal lumen. Enteric fluid retention increases the fecal volume, mechanically stimulating peristalsis.
Dissolved in hot water or milk, at dosages ranging from 10 to 30 grams per day, mannite is recommended as a mild laxative for seniors and children (naturally at lower doses, in the order of 2/15 g) per day in relation to age).
Odorless, mannite has a slightly sweet and pleasant taste, which makes it a valid substitute for sugar for diabetics and the products intended for them.
Mannite: side effects and contraindications
Mannite is well tolerated and at the recommended doses it causes neither colic nor nausea; for a greater laxative effect it can be associated, with due prudence, to other substances with purgative action. Like all laxatives, mannite is contraindicated in the presence of intestinal obstructions, as well as, of course, in case of proven hypersensitivity.
Given the frequent use in old age, it is good to remember that mannite can reduce the absorption of drugs taken simultaneously by oral route, which should therefore be taken at least 2-3 hours apart.
At high doses, it can cause flatulence and abdominal discomfort.
In conclusion, it should be remembered that the laxative effect of mannite is not immediate, but requires from 8-10 hours even a couple of days.
