Non-selective Beta-Blockers and Retroperitoneal Fibrosis: A Potential Factor in Symptomatic Exacerbation a case report.

Retroperitoneal fibrosis is a rare fibro-inflammatory disorder characterized by progressive deposition of dense collagenous tissue within the retroperitoneal space, enveloping vascular and visceral structures. Although most cases are idiopathic, certain pharmacological agents have been implicated in symptom exacerbation. This case report describes an acute deterioration of gastrointestinal function following initiation of a non-selective beta-adrenergic blocker in stable disease.A 45-year-old Caucasian woman with dyslipidaemia and chronic sinus tachycardia underwent exploratory laparotomy for suspected peritoneal malignancy. Histopathology confirmed extensive fibrotic deposition with chronic inflammatory infiltrates and excluded neoplasia, establishing a diagnosis of retroperitoneal fibrosis. During three years of surveillance with serial laboratory assays and magnetic resonance imaging, the disease remained quiescent. To optimize heart-rate control, therapy with a beta-1-selective antagonist was replaced by propranolol 40 mg twice daily, a non-selective beta-adrenergic blocker. Within days, severe crampy abdominal pain, marked distension and altered bowel habits developed despite stable imaging. The close temporal relationship and the established role of beta-2 receptors in intestinal smooth muscle relaxation implicated non-selective blockade in aggravating colonic dysmotility on a background of fibrotic compression. Dietary modifications and low-dose antispasmodics provided only marginal relief.This case illustrates that non-selective beta-blockers may exacerbate gastrointestinal symptoms in retroperitoneal fibrosis by impairing smooth muscle relaxation. In patients with colonic involvement, beta-1-selective agents should be preferred, with careful consideration of cardiovascular benefits versus gastrointestinal risks.