Transitions and Combination Therapy for Pulmonary Arterial Hypertension

Pulmonary arterial hypertension (PAH) is a progressive and often fatal disease. Currently available pharmacotherapies are often suboptimal when used singly, due to either a poor clinical response or a complication from the therapy. As a consequence, transitioning patients from one therapy to another or adding a therapy is a frequently encountered clinical conundrum. This chapter examines the rationale and limited data surrounding transitioning patients from one pharmacotherapy to another and combining individual therapies to produce an improvement in clinical outcomes. Much of the research discussed deals with animal models used to test combination therapies, as there are few clinical trials in human subjects, but this is rapidly changing, as a number of controlled trials are currently either in the planning stages or in progress. Transitions clearly have a role in enhancing the convenience and safety of pulmonary hypertension therapy for some patients. Combination therapy looks promising and may well represent the future of PAH pharmacotherapy.