Actually, Viagra was originally a drug clinically tested for pulmonary hypertension, but the clinical trials revealed an odd side effect which we all know & love. Pfizer cashed in big time with this discovery. There aren't many people with pulmonary hypertension, but tons of men with erectile dysfunction. So yeah, Viagra was actually an surprising discovery that paid off big time.
In the hospitals, it's actually very common for patients to get Viagra for pulmonary hypertension. It's nothing special; it's just the media making this a bigger story than it really is.
There is actually a drug called Revatio approved for pulmonary hypertension & guess what the chemical name is? Sildenafil, the same ingredient in Viagra.
When I worked in the hospital, I would have to call in prescriptions for Viagra into the pharmacy, & they would think I was crazy when I'd say, "Viagra 20mg, Take one tablet three times a day."