Most of the Active Pharmaceutical Ingredient (API) in Sildenafil, Sildenafil citrate, is produced in Pfizers Ringaskiddy complex, County Cork, which is Pfizers largest production facility outside of the United States. Medical uses
Sexual dysfunction
The primary indication of sildenafil is treatment of erectile dysfunction (inability to sustain a satisfactory erection to complete sexual intercourse). Its use is now one of the standard treatments for erectile dysfunction, including for men with diabetes mellitus. Antidepressant-associated sexual dysfunction
Tentative evidence suggests that sildenafil may help men who experience antidepressant-induced erectile dysfunction. Pulmonary hypertension
While sildenafil improves some markers of disease in people with pulmonary arterial hypertension, it does not appear to affect the risk of death or serious side effects. Raynauds phenomenon
Sildenafil and other PDE5 inhibitors are used off-label to alleviate vasospasm and treat severe ischemia and ulcers in fingers and toes for people with secondary Raynauds phenomenon; these drugs have moderate efficacy for reducing the frequency and duration of vasospastic episodes. As of 2016, their role more generally in Raynauds was not clear. High-altitude pulmonary edema
Sildenafil has been studied for high-altitude pulmonary edema, but its use is currently not recommended for that indication. Adverse effects
In clinical trials, the most common adverse effects of sildenafil use included headache, flushing, indigestion, nasal congestion, and impaired vision, including photophobia and blurred vision. Some sildenafil users have complained of seeing everything tinted blue (cyanopsia). This cyanopsia can be explained because Sildenafil, while selective for PDE5, does have a minor level of selectivity for PDE6, which is the phosphodiesterase found in the retina.
Because the middle and inner ears are necessary for hearing, people with complete agenesis of the ears are totally deaf. Minor agenesis that affects only the visible parts of the outer ear, which may be called microtia, typically produces cosmetic concerns and perhaps hearing impairment if the opening to the ear canal is blocked, but not deafness. == References ==