What is known about the reimbursement of Viagra
Coverage of Viagra/Sildenafil for erectile dysfunction by health insurance plans is a contentious issue in developed countries. There are data of the limitations (6 per month) and co-payments (26.6%) by patients  in the US.
The costs for Viagra/Sildenafil for PAH (pulmonary artery hypertension) appear to be covered by health insurances in the US.