Physiology of GERD and Treatment Response

Study Overview
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Brief Summary
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This study is designed to assess the physiologic and behavioral mechanisms associated with enhanced medication effects in adult patients with functional GERD-related symptoms.

Detailed Description
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Subjects will complete questionnaires regarding their GERD-related symptoms and have a visit with a study clinician regarding their symptoms. Heart rate variability and galvanic skin response will be measured in the patient-provider dyads and the visits video recorded. Subjects will receive a two-month supply of amitriptyline (10 mg/day), along with instructions for taking it. Subjects will complete a daily GERD symptom diary during the first and eighth weeks of the study. At the end of the 8-week observation period, subjects will complete follow-up measures of GERD symptom severity and quality of life.

Official Title
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Physiology of GERD and Treatment Response

Conditions
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GERD

Intervention / Treatment
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* Drug: Amitriptyline


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Adults ages 24-64 years old Functional heartburn (defined as <4% of time with reflux on 24 hour pH manometry) symptoms 3 or more days per week with an average daily symptom severity of 3 or more on a 7-day baseline symptom diary English language proficiency Willingness to be videotaped and connected to physiologic monitoring devices during the visit Willingness to take amitriptyline daily for 8 weeks following study visit 1 Exclusion Criteria: Diagnosis of Crohn's disease, systemic sclerosis, known active ulcer disease, gastric cancer, or untreated/active Barrett's esophagitis based on subject self-report and/or medical record review Heavy alcohol use (> 6 drinks/week for women and > 13 drinks/week for men) based on subject self-report Pregnant, attempting to become pregnant, or breast-feeding Dementia or significant memory difficulties as determined by the study team and medical record review Severe, unstable psychiatric disease based on subject self-report, study team determination, and/or medical record review Bipolar disorder, concurrent treatment with a SSRI or another antidepressant that interacts with tricyclic antidepressants Prolonged QTc or severe heart disease History of seizure disorder Severe liver impairment - e.g., cirrhosis, hepatocellular carcinoma, hepatitis Currently taking a tricyclic antidepressant, allergy to tricyclic antidepressants, or another medical contraindication to taking amitriptyline or related medications Greater than 15 doses of nonsteroidal anti-inflammatory drugs (NSAIDS) within the prior 30 days (aspirin ≤ 325 mg daily permitted) or ongoing NSAID use at a level deemed likely to interfere with the study Failure to complete the baseline symptom diary for at least 6 of 7 days Change in GERD treatment regimen within the last 2 weeks (subjects may use antacids, H2 receptor blockers, and/or proton pump inhibitors as long as they are symptomatic on a stable regimen) Allergy to adhesives Inability to provide informed consent In the opinion of the investigator, unable to comply with the study protocol or has a condition that would likely interfere with the study

Ages Eligible for Study
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Minimum Age: 24 Years
Maximum Age: 64 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Amitriptyline<br>Amitriptyline 10 mg daily | Drug: Amitriptyline<br>* Amitriptyline tablet<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in GERD Symptoms | Change in the average daily GERD symptom severity score over a 7-day period from baseline to the last week of the study in the expanded vs. standard group. GERD symptom severity is based on the sum of scores assessing the severity of daytime heartburn, nighttime heartburn, and acid reflux each on a 0-4 point scale (none, mild, moderate, severe, very severe; higher scores signify worse symptoms). Possible score range = 0 - 12. Change score calculated as average score at 8 weeks minus average score at baseline. For statistical testing, we used a general linear model of post-GERD symptoms adjusted for baseline GERD symptoms and randomization assignment. | Time 0 (baseline) to 8 weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Relationship of Physiologic Concordance in Skin Conductance Between Patient and Physician With Patients' GERD Symptom Change | Concordance in skin conductance response (SCR) between patient and physician was calculated using an established approach to create a single index value for the visit (baseline). Average slopes of the SCR were calculated in moving 5 second windows, offset by 1 second. Pearson correlations between time-locked patient and physician SCR slopes were calculated over successive 15 second windows. A single session index was calculated from the ratio of the sum of the positive correlations across the entire visit divided by the sum of the absolute value of the negative correlations across the entire visit. To reduce skew, the natural logarithm of the index was calculated. An index value of zero reflects equal positive and negative correlations, a value greater than zero reflects more concordance in SCR than not, while a value less than zero reflects less than 50% concordance. In the statistical analysis, we included change in GERD symptoms from baseline to 8 weeks. | Time 0 (baseline) to 8 weeks. |