Pulmonary arterial hypertension specific medication use at enrolment among previously diagnosed patients. 184 (7%) of patients were not on a prostaglandin, phosphodiesterase type-5 inhibitor or endothelin receptor antagonist. Pulmonary arterial hypertension specific medication use at enrolment among previously diagnosed patients. 184 (7%) of patients were not on a prostaglandin, phosphodiesterase type-5 inhibitor or endothelin receptor antagonist. Of these, 88 were on calcium channel blockers for the treatment of pulmonary arterial hypertension. M.D. McGoon, and D.P. Miller Eur Respir Rev 2012;21:8-18 ©2012 by European Respiratory Society