Does Omeprazole Decrease Intestinal Calcium Absorption?

University of Wisconsin (UW)

Status and phase: Completed; Phase 4

Conditions: Osteoporosis; Achlorhydria; Hip Fracture; GERD

Treatments: Drug: Omeprazole

Study type: Interventional

Funder types: Other

Identifiers

NCT00582972

H-2007-0179

07-1235-03

Details and patient eligibility

About

The purpose of this study is to measure the effect of omeprazole on intestinal calcium absorption in postmenopausal women.

Full description

Existing literature makes it unclear whether proton pump inhibitor therapy truly decreases intestinal calcium absorption. Up to 25 postmenopausal women will participate in this study. The primary study outcome is the change in intestinal calcium absorption following omeprazole therapy 40 mg daily for 30 days. The secondary outcomes include the change in urine n-telopeptide.

We will interview women and review their medical records to determine eligibility. Eligible subjects will undergo three calcium absorption studies. The first 2 studies will determine the monthly variation in calcium absorption, while the 3rd study will occur after taking 40 mg of omeprazole daily for 30 days. Women will present to the research unit in the early morning and receive an oral and intravenous calcium tracer with breakfast. Over the next 24 hours, we will collect all urine for measurement of its calcium content. During the first stay, we will measure each subject's gastric pH by collecting gastric fluid from a temporary nasogastric tube. In consenting subjects we will collect one tube of blood, isolate its DNA.

Enrollment: 23 patients

Sex: Female

Volunteers: Accepts Healthy Volunteers

Inclusion criteria

• Women at least 5 years past menopause, defined as the last date of menses

Exclusion criteria

• Allergy/Intolerance to orange juice
• Allergy/Intolerance to omeprazole or other PPI therapy
• Use of drugs that interact with omeprazole including oral anti-fungal agents, coumadin, diazepam, phenytoin & tacrolimus
• Use of antacids, PPI or H2-blocker therapy within the past two months
• Intestinal conditions associated with malabsorption or low gastric acid levels including Crohn's Disease, ulcerative colitis, pernicious anemia, bacterial overgrowth, celiac sprue, chronic diarrhea or use of antibiotics within the past month
• Known Stage 4 or 5 Chronic Kidney Disease, defined as an estimated GFR <30 cc/minute
• Use of medications known to interfere with calcium metabolism, including oral steroids or anticonvulsants

Trial design

23 participants in 1 patient group

Experimental

Experimental group

Description:

Subjects will receive omeprazole 40 mg daily for 30 days

Treatment:

Drug: Omeprazole