PDE5 inhibitors and the heart

From: http://circ.ahajournals.org/cgi/content/full/110/19/3149 Summary There are currently 3 PDE5 inhibitors available for the treatment of ED. All are effective in patients with organically based ED, including ED due to vascular disease. Sildenafil and vardenafil have relatively short half-lives of 4 hours, whereas the half-life of tadalafil is 17.5 hours. These agents are all mild vasodilators and have minimal effects on blood pressure. Sildenafil, vardenafil, and tadalafil are all contraindicated with nitrate use. Should a patient develop chest pain while taking sildenafil or vardenafil, nitrate may be administered under supervision at 24 hours (and possibly earlier); should a patient take tadalafil and develop chest pain, nitrate may not be given until at least 48 hours after the tadalafil dose and then again, only under close monitoring. -Blockers are a contraindication to the use of vardenafil. Except for 0.4 mg tamsulosin, -blockers are a contraindication to the use of tadalafil. Sildenafil >25 mg should not be given within 4 hours of an -blocker. Doses of sildenafil of 25 mg may be administered at any time in relation to an -blocker. Vardenafil should not be administered to patients taking class IA or III antiarrhythmic drugs or to patients with congenital QT prolongation. The PDE5 inhibitors do not adversely affect total exercise time or time to ischemia during exercise stress testing. The PDE5 inhibitors are safe to administer to patients taking antihypertensive medicines (except for the -blockers, as described earlier). The PDE5 inhibitors are effective for the treatment of ED in patients with cardiac disease, including patients with chronic coronary artery disease57 and hypertension. Data from controlled clinical trials do not suggest an increase in myocardial infarction or death rates in patients taking PDE5 inhibitors. These agents appear safe and effective in most patient populations but have not been studied extensively in patients with baseline severe or unstable cardiac conditions.