Lubiprostone Effects on Visceral Pain Sensitivity

Study Overview
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Brief Summary
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The purpose of this research study is to determine how Lubiprostone, a medication used to treat irritable bowel syndrome with constipation predominant symptoms (IBS-C), works to reduce clinical pain. Lubiprostone acts in the small intestine to cause an increase in the secretion of chloride, water and sodium. The increased fluid causes food residue to move through the bowel more quickly and makes the stools softer. First, we want to test the idea that Lubiprostone works by making a person less sensitive to pain. Second, we want to confirm that Lubiprostone decreases the time it takes fecal matter to travel through your GI tract, referred to as transit time.

Detailed Description
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Subjects will be enrolled in an 8-week study requiring a total of 7 visits to the UNC Center for Clinical and Translational Research. The protocol is divided into 4 two-week periods: (1) Two-week baseline diary symptom monitoring, followed by a barostat test of pain sensitivity. (2) Two-week treatment with either Lubiprostone or placebo, with daily symptom diary recording and barostat test of pain sensitivity at the end. In addition, patients will be tested for whole gut transit time by the radio-opaque marker (Sitzmark) technique in the second week. (3) Two-week washout period, during which patients will continue the symptom diary. (4) Two-week crossover to Lubiprostone or placebo, identical to the second two-week period.

Official Title
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Lubiprostone Effects on Visceral Pain Sensitivity

Conditions
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Irritable Bowel Syndrome

Intervention / Treatment
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* Drug: Lubiprostone
* Drug: Placebo


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: clinical diagnosis of IBS-C meeting Rome III diagnostic criteria for IBS-C age 18 or older Exclusion Criteria: use of laxatives or prokinetics within two weeks prior to the study or during the study use of IBS-specific compounds, opiates, anticholinergics, or any drug likely to cause constipation as a side-effect use of analgesics for 48 hours prior to the study hypothyroid condition history of bowel resection except appendectomy or cholecystectomy psychotic disorder, major depression, substance abuse (other than tobacco), or other psychiatric condition likely to interfere with the conduct of the study. Subjects treated for depression more than 2 years ago or for situational circumstances may be eligible for the study at the investigator's discretion renal disease inflammatory or ischemic disease of the rectum known to be an unreliable subject Because this study involves exposure to radiation, subjects who are pregnant or planning to become pregnant, employees currently working with radiation, and subjects who have participated in research involving radiation within the past year will also be excluded.

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Lubiprostone<br>Lubiprostone 48ug taken daily for 14 days. | Drug: Lubiprostone<br>* 48ug daily taken as 24ug capsules twice per day, in morning and evening.<br>* Other names: Amitiza;|
| Placebo Comparator: Placebo<br>2 capsules containing a substance with no active ingredient taken daily for 14 days. | Drug: Placebo<br>* 2 capsules daily, taken in morning and evening<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Pain threshold |  | 2 weeks | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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IBS, pain threshold, constipation