Gastrointestinal delay

SULFONYLUREAS Acetohexamide (Dymelor), chlorpropamide (Diabinese), tolazamide (Tolinase), and tolbutamide (Orinase) are given with food to prevent gastrointestinal upset. However, because food delays... 

A number of the water-soluble polymers also have adhesive properties which are being extensively evaluated for drug delivery (9). These polymers will adhere to the mucous coating in the gastrointestinal tract, the nose, and the mouth to delay passage and sustain drug release. Those polymers with the best adhesive properties are those with hydroxyl and carboxyl groups. Table II lists some of the bioadhesive polymers and their adhesive properties. 

Returning to Fig. 6, it can be seen that the oral administration of two 15-mg tablets of propantheline 1.5 hours before atenolol delayed the rate of availability of this p-blocker, while increasing its extent of availability [11]. This increased extent might be due to more complete dissolution of the drug, resulting from its increased time in the gastrointestinal tract. 

In studies with normal adult animals, orally administered radiocerium moves rapidly through the gastrointestinal tract. About 0.96 of a cerium nitrate solution administered orally to rats was excreted within 24 hours (Sagan and Lengemann, 1973). However, external irradiation of the gastrointestinal tract with a 137Cs source (800 R) delayed excretion of the radiocerium. Only about 0.85 of the administered cerium was excreted by 3 days but 0.992 was excreted by 4 days. In swine, 0.98 of an oral dose of radiocerium was excreted by 3 days (Miller et al., 1969) while in cattle, radiocerium placed in the rumen required 3.7 days for 0.9 of the dose to be excreted. Fecal excretion of the cerium still occurred after 4 days. When radiocerium was placed in the abomasum of cattle, it was almost entirely voided in 1.2 days. 

These are called delayed hypersensitivity reactions since they normally occur 6-24 hours after exposure. A cell-mediated allergy involves the interaction of food allergens with sensitised lymphocytes, which usually occurs in the gastrointestinal tract. The sensitised lymphocytes produce lymphokines and the generation of cytotoxic T lymphocytes. These latter cells destroy other intestinal cells, including the epithelial cells that are critical for absorption. 

Field First Aid Decontaminate At Once for All Exposed Victims Although sulfur mustards cause cellular changes within minutes of contact, the onset of pain and other clinical effects are delayed for one to twenty-four hours. Sulfur mustards are alkylating agents that may cause bone marrow suppression and neurologic and gastrointestinal toxicity. However, the biochemical mechanisms of action are not clearly understood by anyone. The death rate from exposure to sulfur mustard during World War I was 2-3 percent,... 

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