Enteric-release glyceryl trinitrate in active Crohn's disease: a randomized, double-blind, placebo-controlled trial

Mucosal ischaemia may contribute to the pathogenesis of Crohn's disease. Microvascular abnormalities have been found in colonic resection specimens, and mucosal levels of constitutive nitric oxide synthase are reduced.

To assess the efficacy of a novel, enteric-release formulation of the nitric oxide donor, glyceryl trinitrate, aimed at increasing the mucosal circulation and relaxing smooth muscle in the affected bowel.

The trial was randomized, double-blind and placebo-controlled. Baseline disease activity was assessed by a structured symptom diary, with blood tests and a quality of life assessment. Patients with a Crohn's disease activity index of > or = 150 and < 450 were randomized to receive 12 weeks of either glyceryl trinitrate (initially 6 mg twice daily, increasing to 9 mg twice daily after 6 weeks) or an identical placebo. Assessments were repeated at 6 and 12 weeks.

Seventy patients (22 male) entered the study; 34 were given glyceryl trinitrate and 36 placebo. At 12 weeks, there were no differences between the treatment groups in terms of Crohn's disease activity index, pain, stool frequency, inflammatory markers or quality of life scores.

Enteric-release glyceryl trinitrate did not benefit patients with mild to moderately active Crohn's disease. Whilst ischaemia may contribute to the pathogenesis of Crohn's disease, our results fail to provide supportive evidence for this hypothesis.