Viagra (sildenafil) is one of the most widely-known prescription drugs and often referred to as the little blue pill. It is the first phosphodiesterase 5 (PDE5) inhibitor approved to treat erectile dysfunction (ED).
ED is a common sexual problem for men and its frequency increases with age.
Over 100 million men worldwide suffer from ED and it was found that men belonging to 40-70 years of age group experienced some degree of ED.
The discovery of sildenafil wasn’t exactly a planned event as the compound was originally developed by Pfizer for the treatment of hypertension angina pectoris i.e. chest pain due to heart disease. During the heart clinical trials, researchers found that the drug was more effective at inducing erections than treating angina.
Realizing that ED is an unmet medical need and hence in1998, the FDA approved Viagra, the first oral treatment for erectile dysfunction under a priority review.
Viagra had the fastest initial sales growth following its launch. Pfizer promoted Viagra and ED awareness via direct-to-consumer advertising that promoted men to seek medical advice and a prescription from their doctors.
Erectile dysfunction is the disability to achieve and maintain an erect penis for sexual function. It can lead to performance anxiety, a negative impact on self-esteem and personal relationships, and clinical depression.
Viagra increases the blood flow to the penis leading to an erection and does not result in an erection without sexual stimulation. It helps to elevate the levels of a substance known as cyclic guanosine monophosphate that causes the tissues to relax and leads to an inflow of blood, causing an erection with sexual stimulation.
General side-effects of Viagra included headache, flushing, heartburn, vision problems, nausea, dizziness, etc.