The authors are indebted to Ms I. Bronner and Ms D. Rietdiik for their contributions to this study. This study was supported by a grant from Astra Pharmaceuticals Inc., Zoetermeer, the Netherlands.
Effect of short- and long-term treatment with omeprazole on the absorption and serum levels of cobalamin
Version of Record online: 2 OCT 2003
Blackwell Science Ltd, Oxford
Alimentary Pharmacology & Therapeutics
Volume 10, Issue 4, pages 541–545, August 1996
How to Cite
SCHENK, B. E., FESTEN, H. P. M., KUIPERS, E. J., KLINKENBERG-KNOL, E. C. and MEUWISSEN, S. G. M. (1996), Effect of short- and long-term treatment with omeprazole on the absorption and serum levels of cobalamin. Alimentary Pharmacology & Therapeutics, 10: 541–545. doi: 10.1046/j.1365-2036.1996.27169000.x
- Issue online: 2 OCT 2003
- Version of Record online: 2 OCT 2003
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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 58Co-cyanocobalamin or protein-bound 57Co-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 57Co-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.