Operating Ease Eludes Mylan

But for each generic-drug maker that complains about the practice, there's another one willing to take advantage of it. Legislation has been introduced in Congress to stop authorized generics.

Even though Pfizer is selling reduced-price Norvasc, it has vowed to "pursue all legal remedies" to protect Norvasc from generic competition in to September 2007.

Pfizer says it has until then because it has secured from the FDA six extra months of marketing exclusivity for Norvasc. Federal law permits this extra protection, known as pediatric exclusivity, if a company conducts tests of a drug to determine if it will help children.