Treatment of PH
Treatment of PH
Pulmonary hypertension (PAH) refers to a variety of diseases with different pathophysiologies. Therefore, the efficacy and side effects of drug therapy might not be the same in all types of PH.
First of all, PH patients should be advised not to exercise too much, since this causes a dramatic increase in pulmonary artery pressure. Oxygen therapy helps to alleviate dyspnea and RV ischemia, and prevents further vasoconstriction.Drug treatment of PH is both specific – aimed at the 3 disturbed pathways – and conventional. The medication has been approved for idiopathic PH, and some types of PH in auto immune disease and interstitial lung disease. The prostacyclin pathway
Addition of prostacyclin (epoprostenol, treprostinil and iloprost) increases the vasodilation of the lung vessels. The nitric oxide pathway
Sildenafil (a phosphodiesterase 5 inhibitor) can enhance the
action of NO in vasodilation. The nitric oxide pathway
The effects of elevated ET-1 levels can be inhibited by selective ET-1 receptor antagonists (bosentan, sitaxentan or ambrisentan). Conventional therapy of PH consists of drugs acting as anticoagulants and antihypertensives. Patients with PH have an increased risk for thrombosis. In this case, mostly oral anticoagulants (coumarines) and thrombocyte aggregation inhibitors (aspirin) are used.
Diuretics and calcium channel antagonists are used in order to decrease the pressure in the lung arteries. Diuretics relieve peripheral edema and reduce right ventricular volume overload.
Therapy with calcium channel antagonists (nifedipine and diltiazem) can result in a substantial decrease in pulmonary artery pressure and vascular resistance. Unfortunately, not all patients respond to calcium channel antagonists.