The discovery of the side effects of combining Vigora Oral Jelly (which contains Sildenafil Citrate) with nitrates likely stems from clinical studies and real-world observations following the introduction of Sildenafil (Viagra) for erectile dysfunction (ED) in the late 1990s.

Background

Sildenafil, the active ingredient in Vigora Oral Jelly, works by inhibiting the enzyme phosphodiesterase type 5 (PDE5), leading to enhanced blood flow to the penis. This makes it effective in treating ED.

Nitrates, commonly used for chest pain or angina, also dilate blood vessels to improve blood flow. However, when combined with PDE5 inhibitors like Sildenafil, the effects on blood pressure can be dangerous.

The Discovery

Medical Research and Clinical Trials: The interaction between Sildenafil (or similar PDE5 inhibitors) and nitrates was recognized during clinical trials and later confirmed in post-marketing reports. Researchers noticed that combining the two could cause a severe drop in blood pressure, leading to symptoms like dizziness, fainting, and even heart failure.

Mechanism: Both Sildenafil and nitrates lead to vasodilation (widening of blood vessels), and when used together, this effect can be excessive, causing hypotension (abnormally low blood pressure), which can be life-threatening.

Who Discovered It?

While no single individual can be credited with this discovery, it became evident through medical reports, clinical studies, and pharmacovigilance data after Sildenafil was approved for ED treatment. The combination's risks were highlighted in FDA warnings and medical guidelines shortly after Sildenafil’s release.