PDE5A and chronic obstructive pulmonary disease: In case of pulmonary hypertension optimal treatment depends of course on the underlying disorder, but could consist of anticoagulants, optimizing treatment for COPD and other lung disorders including oxygen therapy, a trial period with calcium channel blockers (may be either beneficial or detrimental), digoxin, or advanced therapy including prostanoids, endothelian receptor agonists and PDE5 inhibitors.