respectfully ...
Viagra was originally developed as a treatment for high blood pressure. The notorious side effect was discovered during trials.
Given the notoriety of the side effect, a well designed study would correct for such activity. Not sure how ... ask the participants how often?
In any case, it should not be surprising that some drugs have beneficial effects beyond those envisioned in their initial development and trials.
the side effect is profoundly healthy....the study group would need to be those who take, but then do not participate in the normal activity which follows
in any event...it’s good to read of beneficial side effects nowadays instead of toxic/deadly ones
I think it was a drug for Tx of Pulmonary Hypertension.
Specifically developed for Right Sided Heart Failure, for which it has/had a Brand name patented as Revatio. The dosage at 80 mg/day.
It was during the heart failure original trials/research of the agent, that a notable side effect was found from the alleviation of the blood pressure issues in vascular tissue beds.. like the male organ. This, combined with impressive research at the Vascular Biology Working Group (Univ. of FL) describing the nitric oxide (antioxidants involved in, etc) cascade- that put together the approval of Viagra brand.
Prior to this- gel nitroglycerine (usually used to alleviate cardiac angina) was used to achieve erections transdermally absorbed (with a noted side effect for females of nitroglycerine-— massive headaches. truth). Diabetics found some relief of their neuropathy in that region. Viagra having a later discovered nitroglycerine contraindication (caused by heart attacks during intercourse, viagra and nitroglycerine taken together by individuals, as well as nitroglycerine administered to older Viagra users in arrythmia/chest pain, by emergency svcs/EMTs etc. Nitro contraindicated with any of the viagra class of agents.