Prescribing of anti-osteoporotic therapies following the use of proton pump inhibitors in general practice

Purpose To determine the association, if any, between the prescribing of proton pump inhibitors and drugs for the management of osteoporosis. Methods The study employed a retrospective cohort design using the Irish Health Services Executive (HSE) Primary Care Reimbursement Services (PCRS) pharmacy database, which contains prescription information for 1.2 million people (30% of the population). Those aged 55 years and over were included. Individuals were classified as new PPI users if they initiated PPI therapy after 2003, and those not receiving PPI therapy after 2003 as the comparison group. Subsequent prescribing of anti-osteoporotic therapy was considered from 2004 to 2007 in both groups. Adjusted odds ratios (OR and 95%CIs) were determined by logistic regression, adjusting for age, gender and medications, which potentially affect bone mineral density. Results 442341 patients were identified, 209 175 were PPI users and the 233 166 were used as the comparison group. The odds ratio (95%CI) for the prescribing of anti-osteoporotic therapies following the prescribing of PPIs was OR = 1.69 (95%CI 1.66 1.72) compared to not receiving any PPI therapy, when adjusted for age and sex. When adjustments were made for other confounders, the OR decreased to OR = 1.26 (95%CI 1.23-1.28). The strength of the association increased with increasing duration of PPI therapy 6-12 months OR = 1.19 (95%CI 1.15-1.23) and for >24 months, OR = 2.09 (95%CI 2.04, 2.13) compared to <3 months. The OR also increased with increase in dose of therapy. Conclusion The results of the study indicate the association between the prescribing of bisphosphonates following the use of proton pump inhibitors may be clinically relevant. Copyright (C) 2010 John Wiley & Sons, Ltd.