Drug Companies Merge

Two of the biggest drug developers in the pharmaceutical industry are becoming one.

Pfizer is agreeing to pay $68 billion for rival company Wyeth.

The deal will increase Pfizer's revenue by half and adds strength in biotech drugs,vaccines and over-the-counter products like Advil and Robitussin.

Both companies are facing stiff generic drug competition --Pfizer's Lipitor patent expires soon.