Drug giant Pfizer (NYSE:PFE) inked a $3.6 billion deal on Tuesday to snap up King Pharmaceuticals (NYSE:KG) for a 40% premium.

The deal calls for Pfizer to pay $14.25 in cash for Bristol, Tennessee-based King Pharmaceuticals, which should allow the world’s biggest drug maker to strengthen its pain medicine portfolio.

Pfizer said the deal represents a 40% premium to King’s closing price on Monday and a 46% premium to its one-month average closing price.

Pfizer said it sees the deal adding to its 2011 and 2012 non-GAAP EPS by 2 cents a year. By 2013, the company sees the deal boosting its non-GAAP EPS by 3 to 4 cents a year for at least three years.

By scooping up King, Pfizer will get its hands on the Meridian auto-injector business for emergency drug delivery, which includes the EpiPen. In addition to a wide-ranging animal-heath business, King has a number of pain products that could compliment Pfizer’s own offerings, including Avinza, the Fletor Patch and Embeda.

“We are highly impressed by King's innovative products and technology in the pain relief disease area, as well as by its success in advancing promising compounds in its pipeline,” Pfizer CEO Jeffrey Kindler said in a statement. “The combination of our respective portfolios in this area of unmet medical need is highly complementary and will allow us to offer a fuller spectrum of treatments for patients across the globe who are in need of pain relief and management.”

Pfizer said the acquisition isn’t expected to impact its 2010 guidance and it still sees it meeting its 2012 financial guidance. Pfizer sees cost savings of $200 million by the end of 2013. The companies see the transaction closing in the late fourth quarter or in the first quarter of next year.

“By bringing together King's capabilities in new formulations of pain treatments, designed to discourage common methods of misuse and abuse, with Pfizer's commercial, medical and regulatory expertise, global strength in patient services and reimbursement, and global scale and resources, we believe Pfizer can build on our foundation and take our business to the next level," King CEO Brian Markison said in a statement.

Pfizer’s stock eased 0.4% to $17.30 in the wake of the deal, compared with a drop of 0.5% on the S&P 500. Shares of King surged 39.4% to $14.14, but have still slumped nearly 18% year-to-date.