In theory, no.  Generic drugs are supposed to be just as safe and effective as brand-name drugs.  However, there is some evidence that they may not be:

“The average citizen would want to know that someone is checking that manufacturers are making the drugs they got approval to make,” says William K. Hubbard of Chapel Hill, N.C., associate commissioner for policy and planning for the FDA from 1991 to 2005 (and no relation to Beth). “That’s not happening, and the risk to consumers is potentially huge. I take generic drugs when they’re prescribed for me, but my confidence in them is lower than it was a year ago—and going down.”

Source: Bad Bargain: The Dangers of Generic Drugs – Page 1 – MSN Health & Fitness – Health Topics

This is particularly interesting to me due to the potential legal ramifications of generic drugs differing from their brand-name counterparts in serious ways.  Generic drugs are approved by the FDA through an abbreviated process.  Rather than having to demonstrate safety and effectiveness of their drugs, they are allowed to rely upon the proof submitted by the manufacturer of the brand-name drug.  Instead, the generic manufacturer merely has to show that their drug has the same active ingredient in the same percentage.  I’m simplifying it a bit, but not by too much.  I wonder if (a) the FDA will be forced to take a harder look at generic drugs, and (b) whether there will be additional liability for generic drug manufacturers.