The researchers investigated the effect of sildenafil (Viagra) on esophageal motor function in healthy subjects and patients with hypercontractile esophageal motility disorders.
They reported their results in the June issue of Gut.
A total of 6 healthy male volunteers were enrolled in the randomized double blind study. They participated on 2 separate days, before and 1 hour after oral intake of either sildenafil 50 mg or placebo.
Esophageal manometry was performed to determine vector volume of the lower esophageal sphincter (LOS) and pressure amplitudes of the esophageal body.
Of these volunteers, 4 underwent 12-hour ambulatory esophageal manometry on 2 separate days, once with sildenafil 50 mg and once with placebo.
An activity index for spontaneous swallowing was calculated for every hour of the study.
| Sildenafil lowers LOS pressure and propulsive forces in the esophagus body.
Eleven patients with hypercontractile esophageal motility disorders took part in an open study of the effect of 50 mg sildenafil on manometric features of their disorder. The clinical response to sildenafil was also examined.
In healthy individuals, sildenafil significantly reduced LOS pressure vector volume and pressure amplitudes in the distal half of the esophageal body.
The researchers found that, in 3 of 4 subjects, the inhibitory effect of sildenafil lasted at least 8 hours.
In 9 of the 11 patients with esophageal motor disorders, manometric improvement was observed after taking sildenafil.
However, only 4 of these individuals had an improvement in esophageal symptoms with sildenafil taken as required.
Furthermore, 2 of these 4 patients experienced side-effects and did not want to continue treatment.
Andreas J. Eherer, of the Karl-Franzens University, Graz, said on behalf of the group, "Sildenafil lowers LOS pressure and propulsive forces in the body of the esophagus of healthy subjects, as well as in patients with nutcracker esophagus, hypertensive LOS, and achalasia.
"The effect of sildenafil on the esophageal body may last for up to 8 hours in healthy volunteers."
"A subset of patients with hypertensive LOS or nutcracker esophagus may benefit from sildenafil, but side effects are a limiting factor," it was concluded.