Pulmonary arterial hypertension (PAH) is a progressive disease that causes severe disability and has no cure. Over the past 20 years, a variety of treatment options have evolved for the management of PAH. With an expanded therapeutic armamentarium come more complex decisions regarding treatment options. Agent selection depends upon several factors including efficacy, side effect profile, and cost, as well as convenience of administration. We have undertaken a review of
phosphodiesterase-5 (PDE-5) inhibitors in PAH with a focus on efficacy and safety. A literature search was conducted using the Medline and Cochrane Central Register of Controlled Trials databases (1966-February 2010) for relevant randomized clinical studies. Overall, 10 studies met our inclusion criteria.
Sildenafil was the most commonly studied agent, followed by
tadalafil and
vardenafil. Most trials found that the
PDE-5 inhibitors significantly improved exercise capacity and lowered pulmonary pressures. However, there were conflicting results regarding these agents' impact on improving cardiac function and functional class. Overall, these medications were effective and well tolerated with a relatively benign side effect profile. The
PDE-5 inhibitors are an important option in treating PAH. While most of the published clinical data involved
sildenafil, the other
PDE-5 inhibitors show promise as well. Further studies are needed to determine the optimal doses of this therapeutic
drug class, as well as its effects as adjunctive
therapy with other agents in PAH.