In 1849, an emigre German chemist named Charles (formerly Karl) Pfizer set up shop in Brooklyn. Pfizer's first product was an unglamorous treatment for intestinal worms called Santorin, which was a hit despite a list of alarming side-effects, including green-tinged vision and aphasia. In the early 20th century, Pfizer hit the big time, thanks to its work on a revolutionary new fermentation process. This made it possible to synthesise industrial quantities of new drugs relatively quickly.
It was largely thanks to Pfizer's production expertise that when Allied soldiers landed on the beaches of Normandy in 1944, they took 2.3 million doses of life-saving penicillin with them. After the war, the price of penicillin crashed. So Pfizer began the search for profitable antibiotics, ushering in the era of modern pharmaceutical medicine. By the mid 1950s, Pfizer's UK R&D centre in Sandwich, Kent was up and running - where Sildenafil was discovered in 1996. It became a household name as 'erectile-dysfunction' pill Viagra.
By the 1990s, Pfizer was riding high on the back of a series of lucrative new drugs, including anti-depressant Zoloft, Alzheimer's treatment Aricept and the blood-pressure reducing Norvasc. Like all big pharmas, it faces a more uncertain future, as the high-cost, high-margin business model that has sustained it for the past 60 years runs out of road. New drugs are ever harder to find and patents on its existing portfolio are ageing fast. Profit in 2010 fell 4%, and forecast sales for 2012 are down by $2bn.
Who's the boss?
Brit Ian Read took over from Jeff Kindler in December. Kindler ran the show from 2006, and masterminded the $68bn acquisition of Wyeth in 2009, but fell out with the board over post-merger share price performance.
The secret formula?
Pfizer needs to wean itself off expensive blockbusters and adapt to a world where emerging markets will play an increasingly large role in healthcare priorities. In February, it announced that the historic Sandwich research centre would close, with the loss of 2,400 jobs.
In 2009, Pfizer had 14 blockbuster drugs on its books - the largest such portfolio in the world.
The $2.3bn fine it received in 2009 for illegal marketing - the largest in US history.
HQ: New York City
Net profit: $8.6bn
Annual sales: $50bn
R&D budget: c$8.5bn annually
[All figures for 2009 financial year]