UPDATE 4-United Therapeutics gets FDA nod for oral PAH drug

* Expects to launch oral PAH drug in U.S. in August

* Says Adcirca pricing comparable to Cialis on mg-to-mg basis

* Says distribution will be through retail pharmacies

* Sees launch of tyvaso first week of Sept, if approved

* Shares up as much as 12 pct (Updates share movement, adds analyst's comment)

By Jennifer Robin Raj

BANGALORE, May 26 (Reuters) - United Therapeutics Corp (UTHR.O) said the U.S. Food and Drug Administration approved its orally administered drug to treat high pulmonary blood pressure, sending its shares up as much as 12 percent.

The drug tadalafil -- already approved for the treatment of erectile dysfunction under the brand name Cialis -- will be sold under the brand name Adcirca as a once-daily treatment for pulmonary arterial hypertension (PAH), high blood pressure in vessels connecting the lungs to the heart, with a 40 mg dose.

The company expects to launch the drug commercially in the United States at the beginning of August.

"We expect on an mg-to-mg basis the pricing of Adcirca will be comparable to the pricing of Cialis," Chief Executive Martine Rothblatt said on a conference call with analysts.

The distribution of Adcirca will be through the normal retail pharmacies, Rothblatt said, adding that the company had hired sales representatives in anticipation of the launch and does not require any new hiring.

The drug will compete with Pfizer Inc's (PFE.N) Revatio, a 20 mg pill taken thrice a day.

"Based on the results of our survey as well as conversations with our consultants, we expect Adcirca to capture share from (Pfizer's) Revatio," Lazard Capital Markets analyst Terence Flynn said in a note to clients.

The analyst cited Adcirca's more convenient dosing and lower pricing among the reasons as to why the drug could grab market from the Pfizer drug.

Collins Stewart analyst Salveen Kochnover agreed.

Physicians expect Adcirca to cannibilize Revatio, Kochnover said and raised the price target on the shares of United Therapeutics to $100 from $97. The analyst rates the stock "buy".