The effect of secoverine hydrochloride on stimulated sigmoid motility: a double-blind, placebo controlled cross-over study in irritable bowel syndrome

Bulking agents, antispasmodics and antidepressants for the treatment of irritable bowel syndrome

BACKGROUND

Irritable bowel syndrome (IBS) is a common chronic gastrointestinal disorder. The role of pharmacotherapy for IBS is limited and focused mainly on symptom control.

OBJECTIVES

The objective of this systematic review was to evaluate the efficacy of bulking agents, antispasmodics and antidepressants for the treatment of irritable bowel syndrome.

SEARCH STRATEGY

Computer assisted structured searches of MEDLINE, EMBASE, The Cochrane library, CINAHL and PsychInfo were conducted for the years 1966-2009. An updated search in April 2011 identified 10 studies which will be considered for inclusion in a future update of this review.

SELECTION CRITERIA

Randomized controlled trials comparing bulking agents, antispasmodics or antidepressants with a placebo treatment in patients with irritable bowel syndrome aged over 12 years were considered for inclusion. Only studies published as full papers were included. Studies were not excluded on the basis of language. The primary outcome had to include improvement of abdominal pain, global assessment or symptom score.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted data from the selected studies. Risk Ratios (RR) and Standardized Mean Differences (SMD) with 95% confidence intervals (CI) were calculated. A proof of practice analysis was conducted including sub-group analyses for different types of  bulking agents, spasmolytic agents or antidepressant medication. This was followed by a proof of principle analysis where only the studies with adequate allocation concealment were included.

MAIN RESULTS

A total of 56 studies (3725 patients) were included in this review. These included 12 studies of bulking agents (621 patients), 29 of antispasmodics (2333 patients), and 15 of antidepressants (922 patients). The risk of bias was low for most items. However, selection bias is unclear for many of the included studies because the methods used for randomization and allocation concealment were not described. No beneficial effect for bulking agents over placebo was found for improvement of abdominal pain (4 studies; 186 patients; SMD 0.03; 95% CI -0.34 to 0.40; P = 0.87), global assessment (11 studies; 565 patients; RR 1.10; 95% CI 0.91 to 1.33; P = 0.32) or symptom score (3 studies; 126 patients SMD -0.00; 95% CI -0.43 to 0.43; P = 1.00). Subgroup analyses for insoluble and soluble fibres also showed no statistically significant benefit. Separate analysis of the studies with adequate concealment of allocation did not change these results. There was a beneficial effect for antispasmodics over placebo for improvement of abdominal pain (58% of antispasmodic patients improved compared to 46% of placebo; 13 studies; 1392 patients; RR 1.32; 95% CI 1.12 to 1.55; P < 0.001; NNT = 7), global assessment (57% of antispasmodic patients improved compared to 39% of placebo; 22 studies; 1983 patients; RR 1.49; 95% CI 1.25 to 1.77; P < 0.0001; NNT = 5) and symptom score (37% of antispasmodic patients improved compared to 22% of placebo; 4 studies; 586 patients; RR 1.86; 95% CI 1.26 to 2.76; P < 0.01; NNT = 3). Subgroup analyses for different types of antispasmodics found statistically significant benefits for cimteropium/ dicyclomine, peppermint oil, pinaverium and trimebutine. Separate analysis of the studies with adequate allocation concealment found a significant benefit for improvement of abdominal pain. There was a beneficial effect for antidepressants over placebo for improvement of abdominal pain (54% of antidepressants patients improved compared to 37% of placebo; 8 studies; 517 patients; RR 1.49; 95% CI 1.05 to 2.12; P = 0.03; NNT = 5), global assessment (59% of antidepressants patients improved compared to 39% of placebo; 11 studies; 750 patients; RR 1.57; 95% CI 1.23 to 2.00; P < 0.001; NNT = 4) and symptom score (53% of antidepressants patients improved compared to 26% of placebo; 3 studies; 159 patients; RR 1.99; 95% CI 1.32 to 2.99; P = 0.001; NNT = 4). Subgroup analyses showed a statistically significant benefit for selective serotonin releasing inhibitors (SSRIs) for improvement of  global assessment and for tricyclic antidepressants (TCAs) for improvement of abdominal pain and symptom score. Separate analysis of studies with adequate allocation concealment found a significant benefit for improvement of symptom score and global assessment. Adverse events were not assessed as an outcome in this review.

AUTHORS' CONCLUSIONS

There is no evidence that bulking agents are effective for treating IBS.  There is evidence that antispasmodics are effective for the treatment of IBS. The individual subgroups which are effective include: cimetropium/dicyclomine, peppermint oil, pinaverium and trimebutine. There is good evidence that antidepressants are effective for the treatment of IBS. The subgroup analyses for SSRIs and TCAs are unequivocal and their effectiveness may depend on the individual patient. Future research should use rigorous methodology and valid outcome measures.

Bulking agents, antispasmodic and antidepressant medication for the treatment of irritable bowel syndrome

BACKGROUND

Irritable bowel syndrome (IBS) is a common health problem, often presenting in primary care as well as in internal medicine and gastroenterology outpatient clinics. Therapeutic options are dominated by drug therapies but there is uncertainty about their effectiveness.

OBJECTIVES

The primary objective of this review was to evaluate the efficacy of bulking agents, antispasmodic and antidepressant medication for the treatment of IBS.

SEARCH STRATEGY

A computer assisted search of MEDLINE, EMBASE, PsychInfo and the Cochrane Library was performed for the years 1966-2001; local and national databases were searched in 10 European countries.

SELECTION CRITERIA

Randomised trials comparing bulking agents, antispasmodic or antidepressant medications with a placebo, in IBS patients over 12 years of age. Only studies published as a full paper were included. No language criterion was applied.

DATA COLLECTION AND ANALYSIS

The search identified 687 studies, 66 of which fulfilled all eligibility criteria. After removal of cross-over studies that did not report separately on the first phase, data from 40 studies remained for analysis. Relative risk (RR), risk difference (RD) and standardized mean difference (SMD) along with 95% confidence intervals were calculated for all subgroups. The number needed to treat (NNT) was also calculated where appropriate.

MAIN RESULTS

Forty-one study reports from 40 studies, comprising 78 comparisons, were analysed. These included 11 reports on bulking agents, 6 on antidepressants, and 24 on spasmolytics.BULKING AGENTS: Three studies comprising 159 patients reported a dichotomous outcome for relief of abdominal pain. The pooled RR using a random effects model was 1.22 (95% CI 0.86 - 1.73). Three studies comprising 128 patients reported a continuous outcome for relief of abdominal pain. Using the random effects model, the SMD was 0.68 (95% CI -0.86 - 2.33). Nine studies comprising 482 patients reported a dichotomous outcome for global assessment of improvement. The pooled RR was 1.09 (95% CI 0.78 - 1.50). Five studies comprising 253 patients reported a dichotomous outcome for improvement of symptom score. The pooled RR using a random effects model was 0.93 (95% CI 0.56 - 1.54). Two studies comprising 70 patients reported a continuous outcome for improvement of symptom score; the SMD using a fixed effects model was -0.44 (95% CI -1.20 - 0.31). SPASMOLYTIC AGENTS: Eleven studies comprising 1260 patients reported a dichotomous outcome for relief of abdominal pain. The pooled RR using a random effects model was 1.34 (95% CI 1.13 - 1.59; RD=0.17, 95% CI 0.06 -0.28; NNT=6, 95% CI 4 - 15). Seven studies comprising 467 patients reported a continuous outcome for relief of abdominal pain. Using a fixed effects model the pooled SMD was -0.65 (95% CI -0.94 to -0.35). Sixteen studies comprising 1236 patients reported a dichotomous outcome for global assessment of improvement. The pooled RR using a random effects model was 1.42 (95% CI 1.17 - 1.72; RD=0.20, 95% CI 0.09 -0.30; NNT=5, 95% CI 3 - 11). One study comprising 34 patients reported a dichotomous variable for improvement of symptom score. The RR was 1.33 (95% CI 0.96 - 1.85). Three studies reported a continuous outcome for improvement of symptom score; two studies comprising 66 patients could be pooled. Using a fixed effects model, the SMD was -0.37 (95% CI -0.85 - 0.12). ANTIDEPRESSANTS: Two studies comprising 81 patients reported a dichotomous outcome for relief of abdominal pain. Using the random effects model, the pooled RR was 0.83 (95% CI 0.33 - 2.12). Two studies comprising 101 patients reported a continuous outcome for relief of abdominal pain. The SMD using a random effects model was -0.53 (95% CI -2.29 - 1.23). Four studies comprising 241 patients reported a dichotomous variable for global assessment of improvement. The pooled RR was 1.16 (95% CI 0.78 - 1.73).

AUTHORS' CONCLUSIONS

The evidence for efficacy of drug therapies for IBS is weak. Although there is evidence of benefit for antispasmodic drugs for abdominal pain and global assessment of symptoms; it is unclear whether anti-spasmodic subgroups are individually effective. There is no clear evidence of benefit for antidepressants or bulking agents. The physician should be aware that global assessment is a construct containing various dimensions. For each individual, these will have a different weighting and treatment should be aimed at the most debilitating symptom. Stool problems are by definition part of the IBS symptom complex. Bulking agents may improve constipation and can be used empirically, but should be evaluated at an early stage for individual benefit. Future research should pay attention to study methodology and the use of valid outcome measures.

Reduction by cimetropium bromide of the colonic motor response to eating in patients with the irritable bowel syndrome

Cimetropium bromide is an antimuscarinic compound with antispasmodic properties. Its effect on meal-stimulated sigmoid motor activity in 30 patients with the irritable bowel syndrome, mainly with pain and constipation, has been evaluated. The mechanical activity of the sigmoid colon was recorded with a probe with three open-tipped tubes ending 45, 30, and 15 cm from the anal margin. After a recording period of 60 min, 5 mg cimetropium bromide or saline was given i.v., according to a randomized, double-blind design 5 min before a 1000 calorie meal, and motility was then recorded for 2 h. The meal caused a significant increase in motor activity for 90 min in the saline-treated group. Cimetropium bromide abolished the peak of motor activity 10-20 min after the meal and significantly inhibited postprandial colonic motility for at least 2 h (p less than 0.01). This effect provides a rationale for the use of cimetropium bromide in treatment of the irritable bowel syndrome.

Effect of secoverine on colonic myoelectric activity in diverticular disease of the colon

The effect of secoverine on colonic smooth muscle was measured in patients with diverticular disease and in healthy subjects. The frequency of slow wave activity was determined using the fast Fourier transform (FFT) and peak identification analysis (SWSA). The mean slow wave frequency was similar (6 cycles/minute) in healthy subjects using both analytic methods. The slow wave frequency in patients with diverticular disease was similar to that in healthy subjects. The peak frequency measured with SWSA was uniformly higher than that measured with FFT. Secoverine, a muscarinic antagonist, did not affect the slow wave frequency. Eating a 1000-kcal meal initiates an increase in colonic spike activity (22 +/- 2 spike potential/30 min) (P less than 0.001) in healthy subjects during the immediate postprandial period. The gastrocolonic response in patients with diverticular disease was prolonged for 60 min. Secoverine inhibited the gastrocolonic response in patients with diverticular disease. These studies suggest patients with diverticular disease have a similar slow wave frequency as healthy subjects, the gastrocolonic response is prolonged in patients with diverticular disease, and secoverine inhibits the colonic response.