There is no cure for pulmonary arterial hypertension, although a number of treatments can alleviate the condition. Conventional treatments include anticoagulents, which prevent the formation of blood clots, and drugs that relax the blood vessels, including calcium channel blockers, and prostacyclins such as epoprostenol (Floflan).

HIV-positive patients derive less benefit from conventional therapies for pulmonary arterial hypertension than those without HIV. However, newer treatments seem to work better and long-term safety data in HIV patients suggest they are safe.

One of these drugs, bosentan (Tracleer) is a dual endothelin receptor antagonist that works by blocking the action of endothelin, a hormone which occurs in higher levels in people with pulmonary arterial hypertension, and damages the lung and pulmonary arteries. A trial of this drug in 16 people showed that it caused significant improvements on the patients’ exercise capacity, quality of life, and the functioning of their heart^[1].

Elevated liver enzymes have been reported in people receiving long term treatment with bosentan. The latest two-year data show that the frequency of raised liver enzymes was in fact lower in HIV-infected patients. Thirty-four per cent of HIV-positive patients had raised liver enzymes, compared to 44% of those patients who were not HIV-infected, despite the use of concomitant medications also associated with elevated liver enzymes among the HIV-positive group^[2].