America's top 20 selling prescription drugs

#1 Lipitor for high cholesterol, produced by Pfizer. Sales $8.4 billion.

#2 Zocor for high cholesterol, produced by Merck. Sales $4.4 billion.

#3 Nexium for heartburn,, produced AstraZeneca. Sales $4.4 billion.

#4 Prevacid for heartburn, produced by Abbot & Takeda. Sales $3.8 billion.

#5 Advair Diskus for asthma, produced by GlaxoSmithKline. Sales $3.6 billion.

#6 Plavix for heart disease, produced by Myers Squibbs & Sanofi-Aventis. Sales $3.5 billion.

#7 Zoloft for depression, produced by Pfizer. Sales $3.1 billion.

#8 Epogen for anemia, produced by Amgen. Sales $3.0 billion.

#9 Procrit for anemia, produced by Johnson & Johnson. Sales $3.0 billion.

#10 Aranesp for anemia, produced by Amgen. Sales $2.8 billion.

#11 Enbrel for rheumatoid arthritis by Amgen & Wyreth. Sales $2.7 billion.

#12 Norvasc for high blood pressure by Pfizer. Sales $2.6 billion.

#13 Seroquel for schizophrenia by AstraZeneca. Sales $2.6 billion.

#14 Effexor XR for depression by Wyeth. Sales $2.6 billion.

#15 Zyprexa for Schizophrenia by Eli Lily. Sales $2.5 billion.

#16 Singular for asthma and allergies by Merck. Sales $2.5 billion

#17 Protonix for heartburn by Wyeth. Sales $2.4 billion.

#18 Risperdal for schizophrenia by Johnson & Johnson. Sales $2.3 billion.

#19 Neulasta for side effects of chemotheraphy by Amgen. Sales $2.2 billion.

#20 Remicade for rheumatoid arthritis by Johnson & Johnson. Sales $2.2 billion.

Consider now the level of competition. In the top five selling positions there are five different pharmaceutical companies. Among the top ten selling drugs patents are held by nine different companies.

Of the top 20 selling prescription drugs in the United States three of the drugs are owned by Pfizer. But these drugs face stiff competition as well. Pfizer produces Lipitor for high cholesterol but Merck also competes with Zocor. AstraZeneca sells Nexium for heartburn but Prevacid by Abbot & Takeda, also for heartburn, is nipping on their heels and there is also Protonix by Wyeth.. Several drugs compete in the field of treating anemia and rheumatoid arthritis. There are two major drugs competing for the treatment of schizophrenia.

The fact is that the pharmaceutical industry is far more competitive than is often thought.