Converse of object

• call: He was especially acknowledged for the discovery of a protective factor, which he called prostacyclin, which helps to keep blood vessels healthy.

Adjective modifier

• intravenous: Survival in primary pulmonary hypertension with long-term continuous intravenous prostacyclin.

Modifies a noun

• analog: The 'gold standard ' of treatment, due to its beneficial effect on survival, is epoprostenol, a prostacyclin analog.

• treatment: Should patients deteriorate on this treatment intravenous prostacyclin treatment should be considered.