20.5 : 肺动脉高压的治疗：受体酪氨酸激酶抑制剂和钙通道阻滞剂

Receptor tyrosine kinase inhibitors or TKIs and calcium channel blockers or CCBs are used for pulmonary arterial hypertension or PAH treatment.

TKIs like imatinib target the upregulated growth and mitogenic factors in PAH.

It works by inhibiting the PDGF receptor. This prevents cell proliferation, migration, and contraction in pulmonary artery smooth muscle cells, or PASMCs, and pulmonary vascular fibroblasts.

When administered orally, it can cause severe adverse effects such as subdural hematoma.

CCBs target voltage-dependent, receptor-operated, and store-operated calcium channels.

They effectively block calcium ion influx into PASMCs, inhibiting pulmonary vasoconstriction and vascular remodeling.

CCB therapy typically starts with low doses of drugs like nifedipine, amlodipine, diltiazem or verapamil and gradually increases to their maximal tolerated doses. Some are also available as sustained-release formulations.

CCB therapy can lead to adverse effects, including hypotension, hypoxemia, and deterioration of right ventricular function.