Gastric acid concentration lowering

In addition, steroid ulcer has been related recently to mucin deficiency caused by this therapy. Menguy and Masters injected steroids into rats with denen ated antral pouches (M28). They found substantially decreased mucus secretion, as well as compositional change of antral mucus characterized by decrease in its sialic acid concentration (Fig. 14). They concluded that the steroids interfered with the rate of the mucous barrier renewal, caused decreased mucus production, and lowered the threshold of gastric mucosal susceptibility to peptic digestion. Robert and his associates studied the relationship of the mucus secretion to the development of ulcers in fasting rats (R7), as well as in those given large doses of steroids (R8). They determined mucus content by quantitation of hexosamine and found decrease in concentration and output in rats who developed ulcers. The latter appeared only in that portion... 

Another antibody was experimentally produced in rabbits by injecting pepsin (G5). It was detected by the Ouchterlony technique and precipitation reactions, and may have some clinical significance in producing atrophy of chief cells. Repeated injection of this immune serum into rats also caused decrease in the volume of gastric juice, with lower concentrations of acid and pepsin. The controls injected with antibodies to egg albumin, nonspecific globulins, and saline did not show similar changes (see Fig. ). 

Interactions. Drugs that lower gastric acidity, e.g. antacids, histamine H2 receptor antagonists, impair the absorption of ketoconazole from the gastrointestinal tract. Like all imidazoles, ketoconazole binds strongly to several cytochrome P450 isoenzymes and thus inhibits the metabolism (and increases effects of) oral anticoagulants, phenytoin and cyclosporin, and increases the risk of cardiac arrhythmias with terfenadine. A disulfiram-like reaction occurs with alcohol. Concurrent use of rifampicin, by enzyme induction of CYP 3A, markedly reduces the plasma concentration of ketoconazole. 

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