Sildenafil

Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. Sildenafil citrate, sold as Viagra and under various other trade names, is a drug used to treat erectile dysfunction and pulmonary arterial hypertension. The drug was originally developed by British scientists and then brought to market by the US-based pharmaceutical company Pfizer. Sildenafil acts by inhibiting cGMP-specific phosphodiesterase type 5, an enzyme that promotes degradation of cGMP, which regulates blood flow in the penis. It became available in 1998, and has been the prime treatment for erectile dysfunction. Yet, clinical trials have shown that some common adverse effects of sildenafil exist such as headache, flushing, dyspepsia, nasal congestion and impaired vision...