The clinical significance of an endpoint based on an increase of 1 CSBM/week is uncertain.
Based on the definition of 3 or more CSBM/week, the proportion of responders for all 3 months was small.
Use of a known laxative (bisacodyl) further confounds the assessment of effectiveness.
There is a plethora of OTC laxatives, a few under prescription, all indicated for occasional constipation.
The proposed indication is for the use of Zelnorm ® in chronic constipation of all subtypes. However, the aim of the studies was to demonstrate the effect of Zelnorm on the idiopathic subtype of chronic constipation.
It is unclear which constipation subtype benefited from Zelnorm ® . The contribution to efficacy by C-IBS and outlet obstruction patients is unresolved, because 90% were women, many with a predominance of abdominal symptoms.
A benefit from Zelnorm ® use to laxative abusers is unknown, for they were excluded from studies.
Men were under-represented. No statistical differences between treatments were observed.
Subjects > 65 years were also under-represented (about 10% of all pts). No statistical or numerical differences between treatments were seen.