A single 50-mg dose of the erectile dysfunction drug sildenafil at bedtime can worsen obstructive sleep apnea, report researchers from Brazil and the United States (Roizenblatt S. et al. Arch Intern Med. 2006;166:1763-1767).
Because sildenafil could potentially impair respiratory function by promoting upper airway congestion, relaxation of the pharyngeal muscles, and pulmonary vasodilation, the researchers hypothesized that the drug could exacerbate obstructive sleep apnea, a common condition among men with erectile dysfunction. To test this, the researchers randomly assigned 14 men with severe obstructive sleep apnea to receive sildenafil or placebo and monitored them with all-night polysomnography. On the following night, the groups were switched (men who received the drug were given placebo and vice versa).
Stephenson J. Apnea and Sildenafil. JAMA. 2006;296(19):2307. doi:10.1001/jama.296.19.2307-a