Merck & Co., Inc. (NYSE: MRK) reported earnings per share of 82 cents, but excluding restructuring charges, the pharmaceutical company said it earned 86 cents per share, topping analyst estimates of 83 cents per share. Revenue came in at $6.1 billion for the quarter, a decrease of 1% from the second quarter of 2007, but in line with estimates. Yet the stock is plummeting 10% in after-hours trading, after closing at $35.33, down 6.24% during the session.

This shouldn't really be surprising, Merck is not providing 2008 equity income guidance and any long-term financial performance guidance while it is assessing the effects on the Vytorin/Zetia drugs after the failed study result. It also lowered sales guidance for Gardasil, which may not be surprising. But what is surprising is that the drugmaker also lowered sales estimates for its allergy-fighting Singulair.

If investors thought Merck has its work cut out for it, this earnings report underscored the issue even more. Already punished 35% year-to-date, Merck shares will likely continue to be soft until a clear outlook can be seen. Right now, with so many open question and even the company not willing to make educated predictions, many will likely stay away.