Alfuzosin decreases anal pressure in women with constipation

WASHINGTON — Alfuzosin, an alpha1 receptor antagonist, helped decrease anal pressure in women with constipation, according to data from a study presented at Digestive Disease Week.

“We know that some patients with defecatory disorders have high anal resting pressure,” Subhankar Chakraborty, MD, of the Mayo Clinic in Rochester, Minn., said in his presentation. “While alpha1 antagonists are used to treat urinary symptoms in benign prostate hyperplasia, their role in the treatment of defecatory disorders has not been explored.”

Chakraborty and colleagues conducted the placebo-controlled, double-blind parallel group study in two parts. In part A, they measured anal pressures in patients with functional constipation or constipation predominant irritable bowel syndrome (n = 36) and healthy controls (n = 38) before and after a single dose of immediate release alfuzosin or placebo. In part B, patients who completed part A kept a diary of bowel habits for two weeks but did not receive any medication. In the next two weeks, researchers gave patients either extended release alfuzosin (n = 16) or placebo (n = 15).

The primary outcomes were change in anal resting pressure for part A, and change in spontaneous bowel movements and complete spontaneous bowel movements for part B.

“Compared to placebo, alfuzosin significantly decreased anal resting pressure and also anal pressure during evacuation,” Chakraborty said of their part A findings. “Decrease in pressure during evacuation was only seen in constipated patients.”

However, in their part B findings, researchers found that the drug did not improve bowel symptoms. Chakraborty gave several possibilities for why the extended release had a lack of effect:

Inadequate duration of treatment;

Lower peak drug levels with the extended release form;

Incorrect timing of taking medication relative to meals;

Restoration of internal anal sphincter pressure by compensatory mechanisms over time; and

The drug has no effect on voluntary muscles of the pelvic floor, like the puborectalis, external anal sphincter and levator ani.

Alfuzosin is currently unavailable in the United States. – by Alex Young

Reference :

Chakraborty S, et al. Abstract 257. Presented at: Digestive Disease Week; June 2-5, 2018; Washington, D.C.

Disclosures: Chakraborty reports no relevant financial disclosures. Please see the DDW faculty disclosure index for a list of all other authors’ relevant financial disclosures.