Pharmaceutical companies Mylan (NASDAQ:MYL) and Watson Pharmaceuticals (NYSE: WPI) have announced that they have received FDA approval for generic versions of Pfizer's (NYSE: PFE) Revatio, a drug used to combat pulmonary arterial hypertension, or high blood pressure in the lungs. Revatio also contains sildenafil, which is the same component included in the erectile dysfunction treatment Viagra.

Mylan received approval for sildenafil citrate tablets, 20 mg. Watson got the OK for sildenafil tablets, 20 mg,

Revatio tablets, 20 mg, had almost $340 million in U.S. sales in the 12 months ended Sept. 30, 2012, according to Mylan's press release. Mylan boasts a portfolio of more than 1,100 generic offerings, and has another 172 Abbreviated New Drug Applications pending with the FDA. Watson Pharmaceuticals is the world's third-largest generics prescription drug manufacturer, with more than 750 products marketed globally.

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