Achlorhydric patient

The pharmacist should certainly know which drug dosage forms have been designed as delivery systems for prodrugs and also understand the mechanism whereby the active form is made available within the body. Only then can the pharmacist counsel the physician about why a certain product may be inappropriate for such individuals as an achlorhydric patient, a patient with a gastrectomy, or even possibly a patient with a hepatoportal bypass, if liver metabolism... 

In the diet, vitamin B12 is bound to proteins. Although some release of protein-bound vitamin B12 begins in the mouth, most of the release occurs in the stomach on exposure of food to gastric acid (HC1) and the proteolytic enzyme pepsin. For this reason, either hypo-chlorhydria (abnormally low concentration of HC1 in gastric fluid) or achlorhydria (the absence of HC1 in gastric fluid) may decrease the availability of dietary vitamin B12 for absorption by preventing the activation of pepsinogen to pepsin, the principal enzyme responsible for proteolysis in the stomach. Achlorhydric patients with adequate production of IF may have low normal or subnormal serum B12 concentrations because of failure to liberate B12 bound to food. 

In humans, the occurrence of endocrine cell proliferation and occasionally of carcinoids in achlorhydric patients with nonantral atrophic gastritis has been known for decades [19] and has been related to their excessive hypergastrinaemia [20-22]. However, according to recent studies the achlorhydria carcinoid sequence in humans is more complicated [2]. Nonantral gastric endocrine growths have been classified in hyperplasia, dys-... 

Dolby JM, Webster ADB, Bordello SP, Barclay FE, Bartholomew BA, Hill MJ Bacterial colonization and nitrite concentration in the achlorhydric stomachs of patients with primary hypogammaglobulinaemia or classic peme-cious anaemia. Scand J Gastroenterol 1984 19 105-110. 

Others confirmed (K18) that achlorhydric gastric juice from patients with pernicious anemia had inhibitory activity on gastric secretion. They... 

B36. Brunschwig, A., Clarke, T. H., van Prohaska, J., and Schmitz, R. L., A secretory depressant in the achlorhydric gastric juice of patients with carcinoma of the stomach. Surg. Gynecol. Obstet. 70, 25-30 (1940). 

The presence of gastric acid promotes the absorption of important nutrients by release of minerals, particularly calcium, from their complexed organic forms. However, low-acid states do not appear to predispose to decreased calcium absorption in humans. In contrast, the absorption of ferric iron is decreased in achlorhydric states and in gastrectomized patients. This deficit is related directly to the low solubility of ferric iron at a pH greater than 5.0. Nevertheless, the absorption of heme iron is not compromised, and no evidence exists for a predisposition to iron-deficiency anemia. In the case of vitamin B12, neither PPIs nor H2 receptor antagonists have been implicated in significant alterations in absorption of this compound. 

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