Viagra

Viagra is the brand name for sildenafil, more specifically, sildenafil citrate. It is a drug used to treat erectile dysfunction (impotence) and pulmonary arterial hypertension (PAH).

SNPs in at least 2 genes are associated with poor response to Viagra; these include:

• In the ACE gene: the 4 representing the Alu insertion/deletion polymorphism (rs1799752, rs4340, rs13447447, rs4646994)

• In the GNB3 gene: rs5443