Table 2.

Pulmonary arterial hypertension-specific therapy: A summary of agents used

Entothelin receptor antagonists

Agents used in PoPHT: bosentan, ambrisentan

Mechanism of action: blockade of endothelin receptors

Route of administration: oral

Effects: vasodilation, decrease in PVR and portal pressure

Adverse effects: hepatotoxicity

PDE-5 inhibitors

Agents used in PoPHT: sildenafil, tadalafil, vardenafil

Mechanism of action: inhibition of PDE-5 enzyme

Route of administration: oral

Effects: vasodilation, decrease in portal pressure

Adverse effects: hypotension

Prostacyclins

Agents used in PoPHT: epoprostenol, iloprost

Mechanism of action: prostaglandin analogue, increase in cAMP

Route of administration: epoprostenol IV, iloprost inhalation

Effects: vasodilation, antiaggregation

Adverse effects: flushing, headache, nausea, diarrhea. Problems with IV epoprostenol use: cost, infection, catheter thrombosis, and thrombocytopenia

PAH: Pulmonary arterial hypertension; PoPHT: Portopulmonary hypertension; PDE-5: Phosphodiesterase type 5 enzyme; PVR: Pulmonary vascular resistance; IV: Intravenous.