Pfizer's Streak Is Six

The world's bestselling drug, the cholesterol fighter Lipitor, recorded first-quarter sales of $2.5 billion, up 19 percent. Quarterly sales of Norvasc, the fourth-largest-selling drug in the world as well as the bestselling high blood pressure medication, grew 16 percent to $1.14 billion.

"Four of the world's 11 best-selling medicines are marketed by Pfizer, and 14 of our medicines lead their therapeutic areas," Katen said.

However, some big brand names didn't do well. Sales of the antibiotic Zithromax dropped 15% to $446 million. The impotence drug Viagra recorded a 12% worldwide sales decline to $416 million, with the U.S. market posting a 25% drop to $220 million. (For more on Viagra sales, click here.) Two new competitors - introduced last August and November - have begun taking a bigger piece of market share.

Ken Kulju, of Credit Suisse First Boston, told clients Tuesday that he was impressed by the stronger-than-expected synergy of the Pharmacia deal as well as with administrative expenses and research and development expenses that fell below his estimates. Operating margins were above his forecast.

Kulju, who has an outperform rating on the stock, said sales of Lipitor, Norvasc and several other key products either surpassed or matched his predictions. However, sales of Viagra and Zithromax fell below his estimates (He doesn't own shares; his firm has had an investment banking relationship with Pfizer in the last 12 months).

"Overall, the performance was solid across the board," said Jami Rubin, of Morgan Stanley, in an early Tuesday research note. Rubin, who has an overweight rating on Pfizer, said she was pleasantly surprised by strong sales from Lipitor, Norvasc and the anti-inflammatory drug Celebrex. She also was disappointed by sales of Viagra and Zithromax.

With the prospect of four new products reaching the U.S. market this year, the possibility of four new drug review applications being sent to the Food and Drug Administration, and "a slew of advanced stage projects moving down the development pike," Rubin likes the look of Pfizer's future. The company "is shifting from a defensive cost-cutting story to a new product story," she said. (Rubin doesn't own shares; her firm has had an investment banking relationship with Pfizer in the last 12 months).