Effect of a calcium channel blocker and antispasmodic in diarrhoea-predominant irritable bowel syndrome.
BACKGROUND
Irritable bowel syndrome (IBS) is a colonic function disorder. Both pinaverlum bromide (a selective calcium channel blocker) and mebeverine (an antispasmodic) are reported to be effective in the long-term (12-16 weeks) treatment of IBS patients. Their efficacy in the short-term treatment of IBS patients and colonic transit time is unclear. Furthermore, substance P and neuropeptide Y have either excitatory or inhibitory effects on colonic motility. Whether the efficacy of both drugs is mediated through these neuropeptides remains unknown.


RESULTS
A clinical trial was conducted with 91 patients with diarrhoea-predominant IBS. After basal measurement of the total colonic transit time, IBS patients were randomized to receive either pinaverlum bromide (50 mg, t.i.d.) or mebeverine (100 mg, t.i.d.) for 2 weeks. The symptomatic scores regarding defaecation, total colonic transit time and serum levels of substance P and neuropeptide Y were measured before and after treatments. The daily defaecation frequency was markedly decreased after treatment (pinaverlum bromide, 2.9+/-1.2 vs 2.0+/-1.0, P< 0.05; mebeverine, 2.7+/-1.1 vs 2.1+/-1.0, P< 0.05). The stool consistency became well formed after both treatments (P< 0.05). Both drugs similarly improved the global well-being in these IBS patients (pinaverlum bromide vs mebeverine 73.4 vs 71.8%, P> 0.05). The total colonic transit time was significantly prolonged only after pinaverlum bromide treatment (21.4+/-15.5 vs 30.8+/-14.8 h, P< 0.01). Neither substance P nor neuropeptide Y serum level was significantly changed after either treatments.


CONCLUSIONS
Pinaverlum bromide and mebeverine have similar therapeutic efficacies on diarrhoea-predominant IBS patients. Prolonged colonic transit time may be one of the factors responsible for the efficacy of pinaverlum bromide on the IBS patients. Substance P and neuropeptideY appear less important in the pathogenesis of diarrhoea-predominant IBS.
Lu
C L
CL
Department of Medicine and Surgery, Taipei Veterans General Hospital and National Yang-Ming University, Taiwan.
Chen
C Y
CY
Chang
F Y
FY
Chang
S S
SS
Kang
L J
LJ
Lu
R H
RH
Lee
S D
SD
D002121:Calcium Channel Blockers / Q000627:therapeutic use*; D003109:Colonic Diseases, Functional / Q000097:blood / Q000188:drug therapy*; D003967:Diarrhea / Q000097:blood / Q000188:drug therapy; D005260:Female; D005769:Gastrointestinal Motility / Q000187:drug effects; D006801:Humans; D007124:Immunoenzyme Techniques; D008297:Male; D008875:Middle Aged; D009025:Morpholines / Q000627:therapeutic use*; D009478:Neuropeptide Y / Q000097:blood; D010276:Parasympatholytics / Q000627:therapeutic use*; D010627:Phenethylamines / Q000627:therapeutic use*; D018709:Statistics, Nonparametric; D013373:Substance P / Q000097:blood; D011795:Surveys and Questionnaires; D016896:Treatment Outcome
D002121:Calcium Channel Blockers; D009025:Morpholines; D009478:Neuropeptide Y; D010276:Parasympatholytics; D010627:Phenethylamines; D013373:Substance P; C005096:mebeverine; C013199:pinaverium