SILVER SPRING, Md. (AP) — United Therapeutics Corp. said Thursday the FDA approved its blood pressure treatment Tyvaso. Tyvaso, or treprostinil, is an inhaled drug intended to treat pulmonary arterial hypertension. Under a post-marketing deal, the company will conduct a long-term study to evaluate potential toxicity risks. It expects to complete the post-marketing study no later than Dec. 15, 2013. In March, the drug faced scrutiny from the FDA on concerns over patient instructions. It is already sold as an injection called Remodulin. As part of the approval for the inhaled version, the company will have to alter certain aspects of the Tyvaso inhalation system and perform an analysis on how well the inhalation device is used. United Therapeutics said it plans to launch the drug in September.
