Abbott Laboratories (NYSE: ABT) received an FDA approval last week, but it wasn't the one investors have been waiting for.

Abbott's latest FDA approval is for Simcor, a combination of Niaspan -- Abbott's slow-release niacin -- and the active component of Merck's (NYSE: MRK) Zocor, which isn't patent-protected anymore. Abbott also has a Advicor, which combines Niaspan and lovastatin, the generic version of Merck's Mevacor.

The new drugs probably will have minimal effect on Merck, since Zocor and Mevacor have long since lost their blockbuster status. Patients who switch to Abbott's Simcor or Advicor are more likely to be switching from generic drugs.

The approval wasn't all that unexpected, since all Abbott had to do was show that the combination was safe, and that the drugs didn't interfere with each other. But given Pozen's (Nasdaq: POZN) and GlaxoSmithKline's (NYSE: GSK) FDA problems with their migraine combination product, I'm sure investors gave at least a little sigh of relief on Friday.

The new combination drugs benefit patients, since they have to take only one pill instead of two to help lower their LDL "bad" cholesterol and raise their HDL "good" cholesterol. The strategy of making Niaspan easier to take might be in reaction to the potential for competition from Merck's Cordaptive later this year. Both products are based on niacin, but use different strategies to lower the annoying side effect that causes patients to become flushed.

Abbott's long-term strategy is to show that Niaspan not only improves cholesterol, but also decreases cardiac events like heart attacks. Results from that trial won't be available until 2011 though, so until then, Abbott will need to rely on methods like easier dosing to persuade doctors to prescribe drugs containing Niaspan. And investors will keep waiting for that stent approval.

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