Viagra May Worsen Sleep Apnea

October 9, 2006

For people with severe sleep apnea, taking Viagra (sildenafil) before going to bed may exacerbate breathing problems, according to a study published in the Archives of Internal Medicine and reported by Reuters UK.

Obstructive sleep apnea is a common condition characterized by interrupted breathing – often of ten seconds or more – during deep sleep. It occurs when soft tissues at the back of the throat collapse and seal off the throat passage. The period of no breathing is called an apnea and is followed by a sudden attempt to breathe and initiation of lighter sleep. People with sleep apnea therefore experience less deep sleep and are therefore often drowsy during the daytime.

Impotence and Apnea

Erectile dysfunction or impotence commonly occurs among men with obstructive sleep apnea, according to the study’s authors, Dr Suely Roizenblatt, of Federal University of Sao Paulo, Brazil, and colleagues.

Viagra (sildenafil) is known to prolong the effects of systemic nitric oxide, which are to exacerbate upper airway congestion, muscle relaxation and pulmonary vasodilation.

Clinical Trial

Dr Roizenblatt and colleagues examined how sildenafil (50 mg) affected the sleep of 14 consecutively chosen men with severe obstructive sleep apnea. Participants’ average age was 53.1 years and none of the participants were obese or had cardiovascular or respiratory disease, or any other condition known to interfere with sleep.

Each participant was randomized to receive either sildenafil or placebo before embarking on an all-night sleep study that included a minimum of seven hours of recording time using the technique of polysomnography.

Results showed that participants receiving sildenafil had significantly more episodes of oxygen reduction per hour of recording time (30.3 vs 18.5). This group also had a significantly higher percentage of total sleep time with oxygen saturation below 90% (15.6% of participants vs 7.9%) and significantly higher maximum-duration of desaturation event (72.5 seconds vs 48.1 seconds).

Additionally, participants receiving sildenafil experienced changes to their sleep structure – specifically, an increase in stage 2 non-rapid eye movement (REM) sleep compared with placebo, and decreased deep sleep compared with placebo and compared with the start of the study.

The authors note that, because the sample size was small, the study’s results should not be extrapolated to all obstructive sleep apnea patients: “…it is premature to extrapolate our findings to all individuals with sleep-related breathing disorder…. Nevertheless, sildenafil should be used with caution for treating erectile dysfunction in individuals with a sleep-related breathing disorder."

Sources:
Viagra may aggravate severe apnea, Reuters UK, October 3, 2006.
A Double-blind, Placebo-Controlled, Crossover Study of Sildenafil in Obstructive Sleep Apnea. Suely Roizenblatt et al, Archives of Internal Medicine, volume 166, pages 1763-1767, September 2006.

Posted: October 2006


View comments

Hide
(web2)