<unk> (inhalant) is a prostacyclin vasodilator that is FDA approved for the treatment of pulmonary arterial hypertension (PAH) (WHO Group 1) to improve exercise ability.   Common adverse reactions include cough, headache, nausea, dizziness, flushing, throat irritation, pharyngolaryngeal pain, and diarrhea.
Treprostinil 
Tadalafil
Oxybutynin 
Avanafil
Vardenafil
Arbutamine
Finasteride
Gemeprost