Gastric acid blockers boost risk of iron deficiency

Last Updated: 2016-12-12

By Will Boggs MD

NEW YORK (Reuters Health) - Gastric acid inhibition with proton pump inhibitors (PPIs) and histamine-2 receptor antagonists (H2RAs) is associated with an increased risk of iron deficiency, researchers report.

Gastric acid facilitates iron absorption, so anything that interferes with gastric acid would be expected to have an impact on iron absorption.

Dr. Douglas A. Corley from Kaiser Permanente Division of Research, Oakland, California and colleagues evaluated the risk of a new iron deficiency diagnosis among patients without pre-existing risk factors who were on long-term acid-suppressing therapy.

Patients diagnosed with iron deficiency were more likely than controls to have been dispensed at least a two-year supply of PPIs (3.0% versus 0.9%, respectively) or H2RAs (1.4% versus 0.6%, respectively), according to the November 24th Gastroenterology online report.

The odds of a new diagnosis of iron deficiency was 2.49-fold higher among individuals with at least a two-year prior supply of PPIs and 2.15-fold higher among individuals with at least a two-year prior supply of H2RAs, compared with nonusers.

Higher PPI doses (but not H2RA doses) and longer duration of either acid inhibitor were associated with greater increases in the risk of iron deficiency.

The association between PPI use and iron deficiency weakened with increasing duration since cessation of treatment.

The association between PPI use and iron deficiency was stronger among persons aged 30 to 39 years and 50 to 59 years than among those aged 80 years and older, but the associations did not differ by sex or race/ethnicity.

"These findings do not recommend against acid suppression for persons with clear indications for treatment, but clinicians should exercise appropriate vigilance when prescribing these medications, and use the lowest effective dose," the researchers conclude. "These findings should inform discussions contrasting the known benefits with the possible risks of using these medications."

Dr. Rintaro Hashimoto from Sendai Kosei Hospital, Japan, who has also reported the association between PPI use and iron deficiency anemia, told Reuters Health by email, "Acid suppression methods can cause iron deficiency anemia (IDA), although the risk of IDA is not so high."

He agreed that these findings should not significantly alter the use of these medications. "PPIs and H2RAs are important to prevent GI bleeding and reflux disease," he said. "Of course, we need to pay attention to the existence of IDA in patients on PPIs and H2RAs."

Dr. Corley did not respond to a request for comments.

SOURCE: http://bit.ly/2hlWtgb

Gastroenterology 2016.