Acute exacerbation of pain in irritable bowel syndrome: efficacy of phloroglucinol/trimethylphloroglucinol. A randomized, double-blind, placebo-controlled study.

Abdominal pain is the predominant symptom in irritable bowel syndrome patients. Phloroglucinol and its methylated derivative are antispasmodic agents acting on smooth muscle. To evaluate the efficacy of phloroglucinol/trimethylphloroglucinol on pain intensity during an acute exacerbation of pain of irritable bowel syndrome over a 1-week period treatment. Irritable bowel syndrome Rome II patients seeking medical advice for an acute exacerbation of abdominal pain were randomized to phloroglucinol/trimethylphloroglucinol (62.2 mg P + 80 mg TMP) two pills three times daily or placebo for 7 days. Patients were included if they had a pain with a minimal intensity of 40 on a 100-mm visual analogue scale, and if pain occurred at least 2 days during the week previous inclusion. Three hundred and seven patients were included by 78 general practitioners. The intent-to-treat population included 300 patients, aged of 46.9 +/- 14.8 years (73% female). The relative decrease of pain intensity at day 7 was 57.8 +/- 31.7% vs. 46.3 +/- 34.7% (Delta = 11.5 +/- 3.8%, [CI(95%): 4.0 ; 19.1], P = 0.0029) and the percentage of patients with at least a 50% decrease of pain intensity was 62% vs. 47% (Delta = 15.3 +/- 5.7%, [CI(95%): 4.1 ; 26.5], P = 0.0078) in phloroglucinol/trimethylphloroglucinol and placebo groups, respectively. A 1-week phloroglucinol/trimethylphloroglucinol treatment significantly reduces pain intensity in irritable bowel syndrome patients consulting their general practitioners for pain exacerbation.