Propranolol-exacerbated mesenteric ischemia in a patient with hyperthyroidism

OBJECTIVE: To report a case of acute mesenteric ischemia associated with the use of oral propranolol. CASE SUMMARY: A 59-year-old white man was admitted to the hospital with chronic diarrhea and weight loss. The patient was diagnosed as having hyperthyroidism. Therapy with propylthiouracil 100 mg 3 times daily and propranolol 20 mg twice daily was initiated on an outpatient basis. The following day, the patient was readmitted to our hospital with increased abdominal pain and bloody diarrhea. Angiography revealed superior mesenteric artery occlusion. Antegrade aorta-mesenteric bypass surgery was performed for revascularization, and the patient was discharged 10 days after the surgery. The patient was well both clinically and endoscopically at a follow-up visit 8 months later. DISCUSSION: Although mesenteric ischemia is a devastating illness of varied causes, drug-associated mesenteric ischemia is rarely seen. By decreasing cardiac output and selective vasodilatory receptor inhibition in the splanchnic circulation, propranolol can cause a decline in splanchnic blood flow. An objective causality assessment indicated that propranolol was the possible cause of the arterial occlusion. CONCLUSIONS: Propranolol may rarely be associated with mesenteric ischemia. In cases of newly developed acute abdomen undergoing propranolol therapy, physicians should be aware of this rare and serious adverse reaction to this drug.