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Effect of short‐ and long‐term treatment with omeprazole on the absorption and serum levels of cobalamin
Author(s) -
SCHENK B. E.,
FESTEN H. P. M.,
KUIPERS E. J.,
KLINKENBERGKNOL E. C.,
MEUWISSEN S. G. M.
Publication year - 1996
Publication title -
alimentary pharmacology and therapeutics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.308
H-Index - 177
eISSN - 1365-2036
pISSN - 0269-2813
DOI - 10.1046/j.1365-2036.1996.27169000.x
Subject(s) - omeprazole , cobalamin , cyanocobalamin , medicine , gastroenterology , excretion , proton pump inhibitor , endocrinology , vitamin b12
Aims : To evaluate absorption of protein‐bound and unbound cyanocobalamin before and during treatment with omeprazole, and cobalamin levels in patients on long‐term treatment with omeprazole. Methods : In eight former duodenal ulcer patients absorption of unbound and protein‐bound cobalamin was determined by measuring 24‐h urinary excretion of unbound 58 Co‐cyanocobalamin or protein‐bound 57 Co‐cyanocobalamin during a modified Schilling test. Tests were performed before and during treatment with 20 mg and 40 mg omeprazole daily for 9 days. Serum cobalamin levels were assessed in 25 patients with gastro‐oesophageal reflux disease (GERD) before and during long‐term maintenance therapy with omeprazole. Mean treatment duration was 56 months (range 36–81 months). Results : Urinary excretion of unbound cobalamin was unchanged with both dosages of omeprazole. Excretion of 57 Co‐cyanocobalamin, however, decreased significantly during treatment with both 20 mg omeprazole (mean ±S.E.M.: 1.31±0.20 vs. 0.54±0.17%; P <0.02) and 40 mg omeprazole (1.25±0.26 vs. 0.29±0.06%; P <0.02). Mean serum cobalamin levels (±S.E.M.) before and during therapy with omeprazole in GERD patients were 298±27 and 261±16 pg/mL (normal range 180–900 pg/mL), respectively ( P =N.S.). Conclusions : Absorption of protein‐bound, but not unbound, cyanocobalamin is decreased when measured by a modified Schilling test during treatment with omeprazole. However, no change in serum cobalamin levels was observed in patients with GERD after treatment with omeprazole for up to 7 years.