Dick,
There are numerous drugs out there for PAH. It's a matter of working with your dr's and finding out what works and what doesn't work for you. They also are constantly working on new drugs to improve this condition.
I must admit I just wrote down the drug you mentioned for COPD, and plan on researching it, and possibly asking my Dr's about it. Have a good Wed. humpday.

The drug was approved by FDA this past August. It sells for US$3300 a month. Am waiting to see if they can lower price Not sure of spelling but commercial name is ??OHTIVAYRE.