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

BACKGROUND: Abdominal pain is the predominant symptom in irritable bowel syndrome patients. Phloroglucinol and its methylated derivative are antispasmodic agents acting on smooth muscle. AIM: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: A 1-week phloroglucinol/trimethylphloroglucinol treatment significantly reduces pain intensity in irritable bowel syndrome patients consulting their general practitioners for pain exacerbation.