Best Selling Prescription Drugs In The United States

This and last year were big years for the so called "patent cliff", where drug makers started to face generic competition on some of their biggest money makers.This included some of the biggest drugs in history, including Lipitor and Plavix. Chasing blockbusters is dangerous. AstraZeneca, which has focused on such drugs, recently saw its CEO depart as earnings plunged.
Only a fraction of drugs succeed,  but a look at how much a blockbuster is worth makes it clear why companies continue to chase them.
Here are some of the key facts:

• The top 20 drugs in the United States accounted for $319.9 billion in sales in 2011. 
• The most lucrative drugs of the top ten were those that attempt to prevent heart disease, followed by those that treat depression.
• AstraZeneca has the most drugs in the top ten with three, followed by Bristol-Myers Squibb with two.
• Four of the top ten drugs have recently lost patent protection in the United States, with another joining later this year.

Lipitor - $7.7 billion

Company:
Pfizer US sales in 2011:
$7.7 billion

What does it do: 
Lipitor (atorvastatin) lowers LDLs or "bad cholesterol", reducing the risk of heart attack and stroke.
Important dates:
Approved December, 1996. US patent expired November, 2011.  
The future: 
Pfizer made an effort to keep up sales against generics by aggressively advertising the drug even after the patent expired.. It quietly halted the effort earlier this year. Lipitor sales plunged 42 percent in the first quarter this year.

Plavix - $6.8 billion

Company:
Bristol-Myers Squibb/Sanofi Aventis US Sales in 2011:
$6.8 billion
What does it do:
Plavix (clopidogrel) is an anti platelet agent used to prevent clots, helping prevent heart attacks and strokes.
Important dates:
Approved November, 1997. US patent expired May, 2012.  
The future:
Several generic versions of the drug were approved on May 17th and are now on sale. Both Bristol Myers Squibb and Sanofi have aggressively pursued acquisitions and new research to make up for the loss of their biggest money maker.

Nexium - $6.2 billion

Company:
AstraZeneca US Sales in 2011:
$6.2 billion
What does it do:
Nexium (esomeprazole) treats acid reflux disease by reducing the amount of acid in the stomach.
Important dates:
Approved March, 2000. US patent expires May, 2014.  
The future:
Generic drugmaker Teva won't enter the US market until 2014, but there is already generic competition in Europe. Declining sales have significantly impacted earnings.

Abilify - $5.2 billion

Company:
Otsuka, Bristol-Myers Squibb US Sales in 2011:
$5.2 billion
What does it do:
Abilify (apriprazole) is an antipsychotic and antidepressant.
Important dates:
Approved November, 2002. US patent expires October, 2014.  
The future:
The patent expires in around two years, but a generic will not be available until at least 2015. Still, its an addition to an already steep patent cliff after the BMS lost Plavix.

Advair - $4.6 billion

Company:
GlaxoSmithKline US Sales In 2011:
$4.6 billion
What does it do:
Advair is an inhaled combination of fluticasone and salmeterol for the management of chronic asthma.
Important dates:
Approved August, 2000. US patent expired March, 2012.  
The future:
Though the exclusive patent on the drugs expired in March, GSK isn't seeing generic competition yet. Both Teva and Sandoz (a division of Novartis) have yet to replicate it. GSK is seeking approval of Relovair, a successor drug.  

Seroquel - $4.6 billion

Company:
AstraZeneca US Sales in 2011:
$4.6 billion
What does it do:
Seroquel (atorvastatin) is an antipsychotic used to treat schizophrenia, bipolar disorder, and depression.
Important dates:
Approved September, 1997. The US patent expired September, 2011, but a pediatric extension ran until March of this year.  
The future:
The patent expired in Canada earlier, so generic versions already exists. The big hit to sales of Seroquel has yet to come, but sales across the company are down 11 percent, and the CEO just departed.   

Singulair - $4.6 billion

Company:
Merck  US sales in 2011:
$4.6 billion
What does it do:
Singulair (montelukast) is used to treat asthma and seasonal allergies.
Important dates:
Approved February, 1998. US patent expires August, 2012.  
The future:
Singulair sales could decline by one half or more after it starts to face generic competition in the United States starting in August.

Crestor - $4.4 billion

Still don't eat this.

Company:
Shionogi, AstraZeneca US Sales in 2011:
$4.4 billion
What does it do:
Crestor (rosuvastatin) is used to reduce cholesterol prevent heart disease.
Important dates:
Approved December, 1996. US patent expires November, 2016.  
The future:
With Lipitor's patent expiration, an alternative medication became even cheaper, but the US patent is in force for another 4 years.   

Cymbalta - $3.7 billion

Company:
Eli Lilly  US Sales in 2011:
$3.7 billion
What does it do:
Cymbalta (duloxetine) is a drug used to treat depression and anxiety.
Important dates:
Approved in August 2004, US patent expires in June, 2013.   
The future:
Lilly recently lost exclusivity with its another anti-psychotic Zyprexa which is facing several genetic competitors. The loss of Cymbalta will further pressure revenues.

Humira - $3.5 billion

Company:
Abbott Laboratories US Sales in 2011:
$3.5 billion
What does it do:
Humira (adalimumab) is an anti inflammatory used in autoimmune disorders like rheumatoid arthritis and Crohn's disease.
Important dates:
Approved December 1998, US patent expires December 2016.   
The future:
Humira has some time to go under its current US patent. Sales are expected to rise over the next few years, Reuters expects it to be the top selling drug in the world for 2012, passing Lipitor.