When a Patent of Big Pharmaceutical blockbuster drug’s gets expiry, generic-drug makers step in. Here are the top-selling generic drugs and the branded drugs they’re displacing.

When Big Pharma invents a new drug, it works like a cash machine for these Giant Pharma. With USA patents protecting new discoveries from competition, drug developers Giant like Pfizer, GlaxoSmithKline, and AstraZeneca can charge whatever they want for their little miracles.

Until, that is E day, the patent expiry date. Then it’s goodbye profits, and hello generics! Behind every new drug is a generic copycat. In India, it works in different ways. Any pharma company can produce any drugs that domestic market need. Live is the first.

This year 2009, according to Standard & Poor’s research, branded drug sales are set to decline for the first time. That’s partly due to the economy, but also due to increasing competition from generics. IMS Health, the industry’s clearinghouse for drug sales data, says that $24 billion worth of branded drugs this year will get generic competitors, up from $18 billion last year. The figure will hit $30 billion by 2012.

Launched: January 2005
2008 sales: $900 million
Branded equivalent: Duragesic, by Janssen, 2008 sales of $1.1 billion

Launched: July 2007
2008 sales: $779 million
Branded equivalent: Norvasc, by Pfizer (PFE, Fortune 500), 2008 sales of $2.2 billion

Launched: May 2008
2008 sales: $675 million
Branded equivalent: Toprol, by AstraZeneca (AZN), 2008 sales $807 million

Launched: February 2005
2008 sales: $671 million
Branded equivalent: Lamictal, by GlaxoSmithKline (GSK), 2008 sales $1.6 billion

Launched: September 2008
2008 sales: $610 million
Branded equivalent: Risperdal, by Janssen, 2008 sales $2.1 billion

Launched: July 2008
2008 sales: $609.8 million
Branded equivalent: Prilosec, by AstraZeneca, 2008 sales $1.1 billion

Launched: November 2005
2008 sales: $599 million
Branded equivalent: Zithromax, by Pfizer, 2008 sales $429 million

Launched: December 2006
2008 sales: $521 million
Branded equivalent: Wellbutrin, by Biovail (BVF), 2008 sales $579 million

Where there are generic drugs, there are lawyers. Biovail tried to avoid the coming generic onslaught for its antidepressant Wellbutrin by launching an extended-release version of the drug, called Wellbutrin XL, in August 2003.

Remmember that buying generic drugs is to save you money.

Related posts:

1. World Top Ten Antimicrobial Agents and generic drugs list
2. About generic drugs