Dronabinol increases pain threshold in patients with functional chest pain: a pilot double-blind placebo-controlled trial.

Noncardiac chest pain is associated with poor quality of life and high care expenditure. The majority of noncardiac chest pain is either gastresophageal reflux disease related or due to esophageal motility disorders, and the rest are considered functional chest pain (FCP) due to central and peripheral hypersensitivity. Current treatment of FCP improves 40-50% of patients. Cannabinoid receptors 1 (CB1) and 2 (CB2) modulate release of neurotransmitters; CB1 is located in the esophageal epithelium and reduces excitatory enteric transmission and potentially could reduce esophageal hypersensitivity. We performed a prospective study to evaluate its effects on pain threshold, frequency, and intensity in FCP. Subjects with FCP received dronabinol (5 mg, twice daily; n = 7; average age, 44 years; mean body mass index, 26.7) or placebo (n = 6; average age, 42 years; mean body mass index, 25.9) for 28 days (4 weeks). Chest pain, general health, and anxiety/depression questionnaires were assessed at baseline and at 4 weeks. Subjects underwent an esophageal balloon distention test prior to treatment and on last day of the study. Dronabinol increased pain thresholds significantly (3.0 vs. 1.0; P = 0.03) and reduced pain intensity and odynophagia compared to placebo (0.18 vs. 0.01 and 0.12 vs. 0.01, respectively, P = 0.04). Depression and anxiety scores did not differ between the groups at baseline or after treatment. No significant adverse effects were observed. In this novel study, dronabinol increased pain threshold and reduced frequency and intensity of pain in FCP. Further, large scale studies are needed to substantiate these findings.

Comparison of clinical features in patients with eosinophilic esophagitis living in an urban and rural environment.

Eosinophilic esophagitis (EoE) has been associated with exposure to aeroallergens. Living in different locations (urban vs. rural) could potentially expose individuals to different environmental factors. Currently, there is limited data on the matter, and all was based on small population studies that did not exclude proton pump inhibitor (PPI)-responsive esophageal eosinophilia in their cohort. The primary aim of this study was to determine the prevalence of EoE in an urban versus rural population and compare demographic and clinical characteristics in patients that had been treated with high-dose PPI prior to diagnosis. Esophageal biopsies were obtained from a cohort of patients who presented with symptoms of dysphagia, odynophagia, globus sensation, and heartburn during a 10-year period. Only patients who had biopsies from the mid and distal esophagus with ≥20 eosinophils per high-power field while on high-dose PPI treatment during endoscopy were included. Urban population was defined as >1000 people/square mile, and rural population was defined as ≤1000 people/square mile (U.S. Census Bureau). Demographic data from each group was analyzed for age, sex, body mass index, duration of symptoms, and tobacco use. Chi-square analysis was used for frequencies with statistical significance defined as P ≤ 0.05. A total of 20 718 patients were identified and their records evaluated. From this cohort, 57 (0.28%) symptomatic patients (male/female: 39/18, mean age = 29.5 years) had biopsy-proven EoE (≥20 eosinophils/hpf) while on PPI treatment. Of those EoE patients, 29 (50.9%) reported living in rural area versus 28 (49.1%) living in the urban area. The most common medical history components included asthma (12.3%), and the most common presenting symptoms included dysphagia (50.9%), heartburn (26.3%), and nausea/vomiting (22.8%). The average duration of symptoms, body mass index, and smoking habits did not differ between the groups. Dysphagia was significantly more prevalent in the urban population (37.9% vs. 64.3% P = 0.047), while heartburn and reflux were more prevalent in the rural population (37.9% vs. 14.3 P = 0.043). Asthma was prevalent in both populations without a significant difference (P = not significant). There is no residential variation in the incidence of EoE among patients with non-PPI-responsive esophageal eosinophilia. Dysphagia was more prevalent in the urban population, while heartburn and reflux symptoms were more prevalent in the rural environment. Further exploration of environmental factors and specific allergens may help explain the varying symptoms and causes of EoE.