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Mr. Lamb is a freelance pharmacy writer living in Virginia Beach, Virginia, and president of Thorough Cursor Inc.

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Overall, the number of prescriptions dispensed in 2006 increased slightly from 2007, growing by 103 million. Sales were up 3.8% from the previous year, rising to $286.5 billion.

Generics accounted for 67.3% of the 3.8 billion prescriptions dispensed in the United States last year, according to IMS Health. This statistic goes a long way toward explaining why the growth in dollar sales for drugs was the lowest since 1961. Other reasons the research firm cited for the relatively static performance of the pharmaceutical market were that few significant new medications were approved in 2007, and entire classes of drugs lost orders and sales due to concerns over safety and efficacy.¹

Robust Performers
As it has for several years running, Pfizer Inc’s Lipitor (atorvastatin) took the top spots on the lists of drugs prescribed and sold. Another cholesterol-lowering medication, Teva’s simvastatin, made the biggest leap into the top 10 of prescribed products by moving up from 85th place in 2006. Zocor, Merck’s branded version of simvastatin, fell from 25th in prescriptions and 7th in revenues during 2006 to be completely off both lists in 2007. That slide began when Zocor lost patent protection in the summer of 2007. (See the Top 200 tables below.)

Generally, the ranks of the biggest earners remained unchanged. The only significant newcomer to the top 20 for sales was Vytorin, which combines simvastatin and Zetia (ezetimibe; Merck/ Schering-Plough). Vytorin rose from 30th to 18th in sales. How recent reports that neither Vytorin nor its Zetia component reduces atherosclerosis better than simvastatin alone will affect prescribing and sales remains to be seen.²

Lipid regulators were the second-most prescribed class of drugs, led only by antidepressants. The antidepressants generated 232.7 million prescriptions, whereas the lipid regulators generated 220.9 million scripts. Both classes easily outpaced codeine and combination analgesics, which came in third, with 186.1 million prescriptions.

Except in the cases of lipid regulators, proton pump inhibitors (PPIs), and antidepressants, large prescription volumes were not reflected in large revenues for therapeutic classes. The lipid regulators were the biggest sellers, earning $18.4 billion as a group. They were trailed, in order, by PPIs ($14.1 billion) and antipsychotics ($13.1 billion). PPIs ranked 6th in number of prescriptions during 2007.^3,4

Fewer Blockbusters
Generics accounted for about 20% of drug dollars in 2007, and the loss of market share for brand name drug manufacturers was not offset by the market entry of new blockbusters.5 The FDA approved a 5-year low of 18 new drugs in 2007, whereas products such as Ambien (zolpidem tartrate; sanofi-aventis), Norvasc (amlodipine besylate; Novartis), and Zyrtec (cetirizine; Pfizer) were exposed to generic competition for the first time.^6,7

A Barron’s survey of FDA public records and industry experts revealed that the highest expected number of new molecular entity approvals for 2008 was 29. According to the magazine, only 5 of these possible approvals could be expected to reach $1 billion in annual sales by 2015.⁸

Antidepressants and Antianemia Drugs
Sales losses were also likely due to decisions by prescribers and payers to avoid giving and covering drugs to large groups of patients. IMS and other researchers have pointed to 2005 and 2007 warnings that antidepressant use is possibly associated with suicidality as reasons for slow prescription growth and $1.7 billion in lower sales for drugs in that class.^9,10 Similarly, when evidence that the antianemia injections could potentially lead to clotting problems and more aggressive cancers, the FDA required stricter warnings for erythropoiesis-stimulating agents, such as Ortho Biotech’s Procrit (epoetin alfa) and Amgen’s Aranesp (darbepoetin alfa). Medicare then issued new rules last year denying reimbursement for most uses of the agents.^11,12 Overall sales of the erythropoietins declined from $10.1 billion in 2006 to $8.6 billion in 2007.

Click on table above for larger image

Click on table above for larger image

References

1. IMS Health. IMS Health reports US prescription sales grew 3.8 percent in 2007, to $286.5 billion [press release]. March 12, 2008.
2. Cholesterol Drug Controversy Continues. HealthDay News, March 31, 2008. www.nlm.nih.gov/medlineplus/news/~. Accessed April 3, 2008.
3. Lamb E. Top 200 prescription drugs of 2006. Pharmacy Times. May 2007. Accessed March 29, 2008.
4. IMS Health. 2007 US sales and prescription information. www.imshealth.com/ims/portal/front/~. Accessed March 29, 2008.
5. Generic Pharmaceutical Association. Industry statistics. www.gphaonline.org/Content/NavigationMenu/~. Accessed March 29, 2008.
6. Blum J, Pettypiece S. As drug makers shoot for blockbuster drugs, FDA approvals drop. International Herald Tribune. January 5, 2007. www.iht.com/articles/2007/01/04/bloomberg/bxdrugs.php.
7. Lamb E. Watch for generic blockbusters over next year. Pharmacy Times. November 2007. Accessed April 3, 2008.
8. Bennett J. Pills that could thrill in 2008. Barron's Online. January 15, 2008. online.barrons.com/article/SB120034955929489561.html.
9. Olfson M, Marcus SC, Druss BG. Effects of Food and Drug Administration warnings on antidepressant use in a national sample. Arch Gen Psychiatry. 2008;65(1):94-101.
10. FDA. FDA proposes new warnings about suicidal thinking, behavior in young adults who take antidepressant medications. Press release. May 2, 2007.
11. Ortho Biotech Products. Ortho Biotech revises prescribing information for Procrit (epoetin alfa). Press release. March 7, 2007.
12. Centers for Medicare & Medicaid Services. Medicare posts final national coverage determination for the use of erythropoiesis stimulating agents in cancer and related neoplastic conditions. Press release. July 30, 2007.