Sildenafil is being used by a number of patients with erectile
dysfunction. Some of these patients also may have concomitant COPD. The
effect of sildenafil on lung function is not known. Two patients with
severe COPD and erectile dysfunction reported that their dyspnea
improved when they took oral sildenafil for erectile dysfunction.
Spirometry performed in these patients revealed an improvement in
FEV1 by 24% and 12%. This suggests that, in COPD
patients, oral sildenafil does not have any deleterious effect on
pulmonary function, and in some patients it may produce a modest
improvement in FEV1.