The leader in pharma sales, Pfizer is well known thanks to several household name drugs, including Lipitor, Advil, Celebrex, Zithromax and the ever-abundant "little blue pill," Viagra. As the company looks at the looming Lipitor patent cliff, CEO Ian Read has been searching for new methods to keep revenue high, other than new approved drugs. Recently, the company has been considering spinning off portions of the company to create smaller, more profitable arms, a polar opposite of former CEO Jeffrey Kindler's bulk-up strategy of years past. The company's past purchases and mergers have included King Pharmaceuticals, Warner-Lambert, SUGEN and a $68 billion purchase, Wyeth, in 2009.

Wyeth provided Pfizer with an influx of 17 new drugs and vaccines, including Enbrel, Effexor, Prevnar and Pristiq, and Pfizer declared the merger made them "one of the most diversified companies in the global health care industry." And the company continues to move forward as it focuses on hot areas, including Alzheimer's, oncology and vaccines.

The company's legal woes have caused headaches as well. Pfizer has paid over $340 million in settlements for its menopause treatment, Prempro and has 1,200 cases pending for the anti-smoking drug Chantix. Back in 2009, it paid $1.3 billion for illegal marketing fines for the painkiller Bextra, making it the largest fine in United States history.

Pfizer has stayed in the top two on FiercePharma's annual layoffs list for the past three years, thanks in part to the company's 2009 megamerger with Wyeth, and the pressure could be felt for another five years. The company also placed second in the Top 15 R&D Budgets, with $7.4 billion in 2009. But those numbers will continue to slip as Pfizer looks towards development deals instead of in-house research.