United Therapeutics Corp., of Silver Spring, Md., reported total revenues of $327.5 million for the first quarter, missing analyst estimates of $354 million. Revenue from its pulmonary arterial hypertension franchise included sales of $146.3 million for Remodulin (treprostinil injectable), $113.4 million for Tyvaso (treprostinil inhaled), $20.9 million for Orenitram (treprostinil extended-release tablets) and $45.4 million for PDE5 inhibitor Adcirca (tadalafil).