SAN DIEGO — Somaxon Pharmaceuticals Inc. and Procter & Gamble Co. have entered into a co-promotion agreement for Silenor, a newly approved treatment for insomnia characterized by difficulty with sleep maintenance.

Somaxon said Wednesday that under the pact, the company and P&G will co-promote Silenor (doxepin) with a combined 215 sales representatives in the U.S. market. P&G’s professional health care sales force will promote Silenor to targeted primary care and other high-prescribing physicians, while Somaxon will focus on specialists and other top-decile physicians who treat insomnia.

In addition, P&G will promote Silenor to targeted pharmacies and will provide supplemental managed care support services for Silenor. Somaxon has also granted P&G a right of first negotiation relating to rights to develop and market Silenor as an over-the-counter medication in the United States.

"We are extremely excited to add Procter & Gamble"s highly regarded and tenured professional sales force to our commercialization effort for Silenor," stated Richard Pascoe, Somaxon president and chief executive officer. "With the combined effort of both sales forces, we will target 35,000 of the highest prescribers of insomnia products as well as 25,000 pharmacies, which we believe will allow us to be highly competitive in the insomnia market. In addition, we are excited about the potential to partner with Procter & Gamble for the OTC rights to Silenor as a future life-cycle management opportunity."

"We are thrilled to partner with Somaxon to co-promote Silenor," commented Thomas Finn, president of global health care at P&G. "This opportunity is an excellent fit with P&G Health Care’s current and future business interests, and we are confident P&G’s professional sales force will help Silenor deliver both for patients and in the marketplace."

The term of the agreement runs through Dec. 31, 2012, and is renewable thereafter, according to Somaxon.