On Symptom Laundry Lists in Print and on TV

You've probably gotten a good laugh lately from TV ads that warn men that after taking particular drugs "If you experience an erection lasting more than four hours, consult your doctor." Thanks for the tip.

Other TV ads for new drugs give long lists of "possible side-effects" of the medication being advertised, ranging from serious issues to things that seem trivial, like the seemingly ubiquitous "dry mouth".

Now today I'm reading the latest US News and World Report. It has full-page drug ads, followed by the useless back page that gives info on the clinical trials used, the "possible side-effects", and other warnings and precautions. But this time I was stunned to see a one page ad (for Ambien, a sleep medication) followed by two full pages of such information -- and of course they are in 2-point font, making them impossible to read without a magnifying glass. These have to be the least-read pages of any magazine they appear in.

Two points I'd like to make here:
1 - I'm actually not sure what leads drug companies to provide so much information in both TV ads and print ads. I assume it is either government regulation and/or fear of lawsuits. If anyone knows for sure what the leading cause is, I'd love to hear it.
2 - It seems to be getting worse. The two-page small-print I saw today is one indication of this, but so are some commercials that rattle off warnings and "possible side-effects" with the verbal speed of an good auctioneer.