Good thing that Zoloft is no longer covered by patent protection. Now it will be a lot cheaper for Pfizer Inc. (NYSE: PFE) investors to stock up on the anti-depressant so they can better cope with the drug maker's lousy earnings.

Net income in the second quarter plunged 48% to $1.27 billion, or $0.18 per share, on revenue of $10.11 billion. Excluding unpleasant stuff like restructuring charges, profit was $0.42. On that basis, Wall Street analysts expected profit of $0.50 on revenue of $11.4 billion, according to Thomson Financial.

Investors could take some solace knowing that the company doesn't think things will get much worse. It reaffirmed EPS and revenue guidance for 2007 and 2008. Good thing, too, since the company just cut its 2007 outlook in April.

Still, there wasn't much to cheer about in today's results. Sales of Lipitor, the company's most prescribed product, plunged 13% in the quarter, failing to meet Pfizer's own expectations. Zoloft sales plunged 82% while NORVASC fell 45% and Viagra fell 3%.

Investors expected sales of these drugs to plunge since they lost patent protection. Chief Executive Jeffrey Kindler has cut jobs and closed factories to cut costs. But what the company needs more than anything are new best selling drugs.

Like the minor league system in baseball, drug companies count on their pipelines to replace aging players. Whether investors will give Pfizer enough time to develop its prospects is far from certain.