Advances in the Study of Inhaled Formulations for the Treatment of Pulmonary Arterial Hypertension

Abstract

Pulmonary arterial hypertension (PAH) is a serious disease with reduced systemic circulation and low bioavailability associated with conventional and dosed therapy, which inhaled drugs can avoid. A mean pulmonary artery pressure (mPAP) of ≥25 mmHg ( $1\text{mmHg}=0.133\text{kPa}$ ) at rest or ≥30 mmHg during exercise and a pulmonary capillary pressure or left atrial pressure (PLA) of ≤15 mmHg can be diagnosed with PAH. Pulmonary hypertension is classified into primary PAH and secondary PAH according to the presence or absence of principles or risk factors. The main symptoms of pulmonary hypertension include dyspnoea, syncope, weakness, chest pain, and the presence of varying degrees of peripheral oedema. It is a highly pathogenic and life-threatening disease and can lead to delays in treatment if not diagnosed in time. In the past few years, the studies related to this progressed slowly, which brought great harm to patients with PAH. Reports showed that patients diagnosed with PAH should receive routine preventative care, such as pneumococcal and influenza vaccinations. Inhalation therapy is mainly used for the treatment of respiratory diseases and is of great interest due to the concentration of the drug in the airways and lung tissues. Therefore, the present situation of pulmonary hypertension and the characteristics of inhalation preparation were reviewed in this paper to provide some related cue for the treatment of pulmonary hypertension. In the future, it is necessary to develop more treatment methods for pulmonary hypertension.