Absorption of fats

Salatrim is a mixture of many triglycerides that have the characteristics mentioned above. Because it is partially absorbed, Salatrim does not have the problems associated with Olestra. It does not have any laxative effects nor does it prevent the absorption of fat-soluble vitamins and carotenoids. 

Colesevelam 625 mg tablets 3750-4375 mg/day as a single dose or divided twice daily, with meals colesevelam. Increasing fluid and dietary fiber intake may relieve constipation and bloating. Impair absorption of fat-soluble vitamins. 

Orlistat reduces the absorption of fat-soluble vitamins. Daily intake of a multivitamin containing vitamins A, D, E, and K, as well as 3-carotene, is recommended. Patients should take the multivitamin 2 hours prior to or after the dose of orlistat.31 Since availability of vitamin K may decline in patients receiving orlistat therapy, close monitoring of coagulation status should occur with concomitant administration of warfarin.31 Administration of orlistat in conjunction with cyclosporine can result in decreased cyclosporine plasma levels. To avoid this interaction, cyclosporine should be taken 2 hours preceding or following the dose of orlistat. Additionally, cyclosporine levels should be monitored more frequently.31... 

Bile acids secreted into the small intestine facilitate absorption of fat-soluble vitamins and cholesterol. The majority of bile acids are reabsorbed from the intes-... 

Currently, the only drug on the market that works by blocking the body s absorption of calories is orlistat, which is sold under the brand name Xenical . Orlistat specifically decreases the absorption of fats from food consumed. A further discussion of orlistat and how it works can be found in Chapter 5. 

There is no solid evidence that relates human aging and reduction of carotenoid absorption. In some studies, old people have shown a lower (3-carotene absorption than that of young people (Madani and others 1989), whereas the opposite has also been reported by other studies (Sugarman and others 1991). The absorption of lipid-soluble substances, including carotenoids, is affected by any disease related to the digestion and absorption of fats (West and Castenmiller 1998). Inadequate production of lipase and bile as well as an inadequate neutralization of the chyme in the duodenum affect carotenoid bioavailability (Guyton and Hall 2001). 

Which of the following is a stool softener that has no effect on absorption of fat-soluble vitamins ... 

The answer is c. (Hardman, p 924.) Dioctyl sodium sulfosuccinate (docusate) is a detergent that, when given orally, softens the stool and prevents straining. Mineral oil also softens the stool, but it tends to inhibit the absorption of fat-soluble vitamins and other nutrients. Castor oil, phenol-phthalein, and cascara sagrada are strong laxatives and cause watery stools... 

Other potential adverse effects include impaired absorption of fat-soluble vitamins A, D, E, and K hypernatremia and hyperchloremia GI obstruction and reduced bioavailability of acidic drugs such as warfarin, nicotinic acid, thyroxine, acetaminophen, hydrocortisone, hydrochlorothiazide, loperamide, and possibly iron. Drug interactions may be avoided by alternating administration times with an interval of 6 hours or greater between the BAR and other drugs. 

Orlistat induces weight loss by lowering dietary fat absorption, and it also improves lipid profiles, glucose control, and other metabolic markers. Soft stools, abdominal pain or colic, flatulence, fecal urgency, and/or incontinence occur in 80% of individuals, are mild to moderate in severity, and improve after 1 to 2 months of therapy. Orlistat interferes with the absorption of fat-soluble vitamins and cyclosporine. 

B14. Blomstrand, R., A study on the intestinal absorption of fat in normal adults and in non-tropieal sprue with carbon-labelled oleic acid and palmitic acid. Acta Med. Scand. 152, 129-138 (1955). 

Cholestyramine use is not without limitations. It does not bind chlordecone alcohol, a metabolite of chlordecone that is also excreted in the bile (Guzelian 1981). It has a gritty texture in the mouth, and it causes several gastrointestinal disturbances, which may limit the willingness of patients to take it. It may also interfere with the absorption of fat-soluble vitamins and interact with other medications (Goldfrank 1990). 

The digestion and absorption of fat is considerably more complex than that of carbohydrate or protein because it is insoluble in water, whereas almost aU enzymes catalyse reactions in an aqueous medium. In such media, fat can form small droplets, an emulsion, which is stable in this medium. Formation of an emulsion is aided by the presence of detergents these possess hydrophobic and hydrophilic groups, so that they associate with both the fat and the aqueous phases. Such compounds are known as emulsifying agents and those involved in digestion are mainly the bile salts and phospholipids. 

Bile salts consist of taurine linked to bile acids. The salts are essential for digestion and absorption of fat and also of fat-soluble vitamins and cholesterol. 

Bile helps in the digestion and absorption of fats. Its constituent bile acids (BAs) have detergent properties, and some can be carcinogenic. BAs can act as signalling molecules, entering the nuclei and reacting with the nuclear receptors and this could enhance or reduce BA synthesis. In this way, they control their own levels as well as those of their precursor, cholesterol. This controls cholesterol homeostasis and BA and lipid synthesis. 

At the required dosage, the resins cause diverse gastrointestinal disturbances. In addition, they interfere with the absorption of fats and fat-soluble vitamins (A, D, E, K). They also adsorb and decrease the absorption of such drugs as digitoxin, vitamin K antagonists, and diuretics. Their gritty texture and bulk make ingestion an unpleasant experience. 

Lubricant laxatives. Liquid paraffin (paraffinum subliquidum) is almost nonabsorbable and makes feces softer and more easily passed. It interferes with the absorption of fat-soluble vitamins by trapping them. The few absorbed paraffin particles may induce formation of foreign-body granulomas in enteric lymph nodes (paraffinomas). Aspiration into the bronchial tract can result in lipoid pneumonia. Because of these adverse effects, its use is not advisable. 

Malabsorption Because they sequester bile acids, these resins may interfere with normal fat absorption and digestion and may prevent absorption of fat-soluble vitamins such as A, D, E, and K. 

II. Nutritargeting as a Way of Bypassing Absorption Barriers A. Digestion and intestinal absorption of fat-soluble 202... 

Vitamin A deficiency is worldwide one of the most prevalent nutrition-dependent deficiency diseases. It leads to changes of the respiratory epithelium, which result in repeated infections of the respiratory tract, the main cause of death in vitamin A-deficient children. The difficulty in supplying the respiratory epithelium with vitamin A is that the affected children frequently suffer as well from infections of the gastrointestinal tract with subsequent reduction of the absorption of fat-soluble vitamins. Nutritargeting can in these cases avoid the problems of malabsorption and ensure the micronutrient supply. 

The principal precaution with use of the bile acid resins is the possibility of impaired absorption of other drugs given orally at the same time. Cholestyramine and colestipol can bind many other drugs, such as digitoxin, phenobarbital, chlorothiazide, and warfarin, and delay or prevent their absorption. For this reason, other drugs should always be taken at least 1 hour before or 4 to 6 hours after the resin. The resins can also decease absorption of fat-soluble vitamins. 

Interferes with absorption of many drugs (give other drugs 1 hr before or 6 hr after the resin). May interfere with absorption of fat-soluble vitamins. 

Adverse effects include aspiration pneumonia, perianal pruritus, healing in perianal region may be delayed, unpleasant taste, the absorption of fat soluble vitamins may be affected. Long-term administration is not recommended. 

Mechanism of action Reduces absorption of fats since triglycerides not split Reduces appetite Reduces appetite... 

Roche ( 27 billion in sales). Hoffman-La Roche, Roche for short, has its global headquarters in Basel, Switzerland, and U.S. headquarters in Nutley, New Jersey. It introduced a new class of tranquilizers in the 1960s, including Valium, and makes the antibiotic Rocephin, Invirase for HIV/AIDS, Xenical for treatment of obesity and absorption of fat, Tamiflu for influenza, and Boniva for treatment of osteoporosis. 

The physiological role of vitamin K is in blood clotting and is essential for the synthesis of at least four of the proteins (including prothrombin) involved in this process. Vitamin K also plays a role in the synthesis of a protein (osteocalcin) in bone. Vitamin K deficiency is rare but can result from impaired absorption of fat. Vitamin K levels in the body are also reduced if the intestinal flora is killed (e.g. by antibiotics). Vitamin K toxicity is rare but can be caused by excessive intake of vitamin K supplements. Symptoms include erythrocyte haemolysis, jaundice, brain damage and reduced effectiveness of anticoagulants. 

Abnormalities in protein digestion In individuals with a deficiency in pancreatic secretion (for example, due to chronic pancreatitis, cystic fibrosis, or surgical removal of the pancreas), the digestion and absorption of fat and protein is incomplete. This results in the abnormal appearance of lipids (called steatorrhea, see p. 175) and undigested protein in the feces. 

Intestinal lymphatic transport has also been shown to substantially contribute to the absorption of fat-soluble vitamins [91], ontazolast [26], probucol [16] and others. 

Kuksis, A. 1987. Absorption of fat soluble vitamins. In Fat absorption, ed. A. Kuksis, 65. Boca Raton CRC Press. 

When used for a long time, mineral oil may come to interfere with the absorption of fat-soluble vitamins and other essential nutrients. Lipid pneumonitis may evolve if mineral oil is used as a vehicle for drugs that are taken nasally. 

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