Pulmonary arterial hypertension is a rare, progressive disorder characterized by elevated blood pressure in and blockage of pulmonary arterioles, due to defective endothelial function and abnormal proliferation of the pulmonary artery smooth muscle cells and fibroblasts. Repurposing drugs for inhaled delivery can offer new treatment options and clinical trials have been completed or are underway. Further research is warranted to establish these repurposed, inhaled drugs for use alone or in combination with existing therapies.
Current therapies for pulmonary arterial hypertension do not provide a cure and their use can be limited due to systemic side effects. Consequently, there is a critical need to discover and develop new drugs that target vascular remodeling and provide long-term disease reversal benefits. Drug repurposing can bypass common challenges of drug discovery and offer shorter developmental cycles. This article described the pathology of PAH and discusses a variety of drugs repurposed for inhalation that have undergone or are currently in clinical trials.