The Pharm Exec 50 report for 2008 accounts for prescription drug sales of more than $510 billion. Interestingly, except for Pfizer, GSK, Sanofi-Aventis (numbers one to three, respectively), and Watson (number 50), every company on the list showed positive growth last year, including some solid double-digit performances.

Much of that growth was driven by mergers, of which there were many. Nycomed, for example, almost tripled in size after its purchase of Altana, itself a top 50 company. And because rankings in the Pharm Exec 50 are calculated in US dollars, a number of European companies look better than they might have done. (Roche's prescription drug revenue, for instance, grew by 11% in Swiss francs, but more than 20% in US dollars.)

A key change has been made in the way this year's 50 were assembled. In the past, private companies that did not disclose sales figures were omitted, but this year for the first time estimates are being offered. This mostly affects privately owned European companies, such as Menarini, Servier, and Ratiopharm, though it also means a first-time ranking for Procter & Gamble, whose multi-billion dollar pharmaceutical operation is such a small part of the company that P&G declines to break out the figures by sales of human prescription drugs and vaccines, as reported in annual reports and SEC filings.

Royalty revenue, contract manufacturing, animal health and OTC have not been counted as far as the documents allow. Some accompanying charts are based on figures from IMS health. These are calculated differently, and may disagree with numbers cited in the 50 itself.