Results of a recently published trial suggest pregabalin, a calcium channel alpha-2 delta ligand, may reduce gastrointestinal symptoms of irritable bowel syndrome (IBS) such as abdominal pain, bloating, and diarrhea.

This double-blind, placebo-controlled trial aimed to determine the efficacy of pregabalin in the treatment of IBS gastrointestinal symptoms. The study included 85 adult patients who met the IBS Rome III criteria with at least 3 pain attacks monthly. The patients were randomized to receive pregabalin 225mg (N=41) or placebo (N=44) twice daily over 12 weeks and were asked to complete weekly questionnaires. The primary endpoint of the study was the mean pain Bowel Symptom Scale (BSS) scores weeks 9 through 12.

The average age of the patients was 39.4 years (SD=14.6) and 73 (86%) were female; 38 patients (45%) in the study had diarrhea-predominant IBS, 29 (35%) had mixed IBS, and 18 (21%) had constipation-predominant IBS. The authors also reported that the average BSS scores were 57 (SD=20) for IBS overall, 56 (SD=20) for pain, 32 (SD=32) for constipation, 45 (SD=31) for diarrhea, and 56 (SD=24) for bloating.

Results of the study showed that patients who received pregabalin had lower average pain-BSS scores weeks 9-12 compared to those who received placebo (25 vs 42, respectively; P=.008). Additionally, the overall IBS BSS severity score was found to be lower in patients who received pregabalin (26) compared to those who received placebo (42; P=.009).

The authors also reported that, although differences were seen between the treatment groups for diarrhea-BSS scores (P=.049) and bloating-BSS scores (P=.016) scores, no difference was observed for constipation BSS-scores. Additionally, no difference was observed between the pregabalin and placebo groups when assessing adequate relief (46% vs 36%, respectively; P=.35).

Findings from the study also revealed that at week 12, 63% of patients who received pregabalin had a change in pain score of ≥30 from baseline compared to 45% of patients who received placebo (P=.10). No differences were observed in post‐treatment IBS‐QoL scores between the 2 groups.

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“Our study provides novel and important data suggesting a positive effect of pregabalin on IBS symptoms, particularly for mixed‐type IBS and diarrhea‐predominant IBS patients,” the study authors concluded. They added, “A large multicenter trial of IBS‐D or IBS‐M patients utilizing the FDA outcome should be pursued as pregabalin shows promise and treatment options for IBS‐related pain and mixed bowel habit IBS remain limited.”


Saito YA, Almazar AE, Tilkes KE, Choung RS, van Norstrand MD, Schleck CD, Zinsmeister AR, Talley NJ. Randomised clinical trial: pregabalin vs placebo for irritable bowel syndrome. Alimentary Pharmacology and Therapeutics. 2019. DOI: