significant value for both providers and patients not only from the improved treatment of diseases, but also from a reduction in other healthcare costs such as hospitalization or emergency room costs, increased patient productivity and a better quality of life.

Defending Our Intellectual Property Rights

The loss of patent protection with respect to any of our major products can have a material adverse effect on future revenues and our results of operations. Our performance in 2005 was impacted by loss of U.S. exclusivity of four major products— Diflucan, Neurontin, and Accupril/Accuretic during 2004 and Zithromax in November 2005. In addition, we face the loss of U.S. exclusivity for Zoloft during 2006 and Norvasc and Zyrtec during 2007. These seven products represented 33% of our Human Health revenues and 29% of our total revenues for the year ended December 31, 2004. Zithromax, Zoloft, Norvasc and Zyrtec represented 26% of our Human Health revenues and 22% of our total company revenues for the year ended December 31, 2005.

Intellectual property legal protections and remedies are a significant factor in our business. Many of our products have a composition-of-matter or compound patent and may also have additional patents. Additional patents can include additional composition-of-matter patents, processes for making the compound or additional indications or uses. As such, each of our products has varying patents expiring at varying dates, thereby strengthening our patent protection. However, once the patent protection period has expired, generic pharmaceutical manufacturers generally produce similar products and sell those products for a lower price. This price competition can substantially decrease our revenues.

Patents covering our products are subject to challenges from time to time. Increasingly, generic pharmaceutical manufacturers are launching their products “at-risk”—before the final resolution of legal proceedings challenging their generic products. Wherever appropriate, we aggressively defend our patent rights against such challenges (details of these matters are described in Notes to the Consolidated Financial Statements—Note 18, Legal Proceedings and Contingencies).

Product Competition

We face the loss of U.S. exclusivity for Zoloft during 2006 and Norvasc and Zyrtec during 2007. In addition, some of our products face competition in the form of new branded products or generic drugs, which treat similar diseases or indications. We have been able to limit the impact on revenues by highlighting the proven track record of safety and efficacy of our products. For example, the success of Lipitor is the result of an unprecedented array of clinical data supporting both efficacy and safety.

Expansion and Productivity of Development Pipeline

Discovery and development of new products, as well as the development of additional uses for existing products, are imperative for the continued strong operation of our businesses. The numerous filings, approvals and launches of new Pfizer products and product enhancements during 2005 and in early 2006 evidenced a productive period of R&D. The opportunities for improving human health remain