Bottom x-axis are the names of 26 pharmaceutical companies existing in 1989. Top x-axis are the names of eight pharmaceutical companies existing in 2002. Y-axis runs from 1989 to 2002 in one year increments. This graph plots the mergers among pharmaceutical companies from 1989 to 2002, demonstrating the merger history for the following eight companies:

Pfizer, with 2002 sales of $48 billion:

• Pharmacia AG merged with Upjohn in 1995 to become Pharmacia and Upjohn.
• Pharmacia and Upjohn merged with Monsanto in 2000 to become Pharmacia.
• Warner-Lambert merged with Pfizer in 2000 to become Pfizer.
• Pfizer merged with Pharmacia in 2002 to become Pfizer.

GlaxoSmithKline, with 2002 sales of $30 billion:

• Beecham merged with SmithKline Beckman in 1989 to become SmithKline Beckman.
• Wellcome merged with Glaxo in 1995 to become Glaxo Wellcome.
• SmithKline Beckman merged with Glaxo Wellcome in 2000 to become GlaxoSmithKline.

Merck, with 2002 sales of $21 billion:

• Medco merged with Merck in 1993 to become Merck.

Bristol-Myers Squibb, with 2002 sales of $19 billion:

• Squibb merged with Bristol-Myers in 1989 to become Bristol-Myers Squibb.
• Bristol-Myers Squibb merged with DuPont Pharmaceuticals in 2001 to become Bristol-Myers Squibb.

Novartis, with 2002 sales of $19 billion:

• Ciba-Geigy merged with Sandoz in 1996 to become Novartis.

Roche Holding, with 2002 sales of $18 billion:

• In 1990 Roche Holding acquired its initial stake in Genentech.
• Roche Holding merged with Genentech in 1995 to become Roche Holding.
• In 1999, Novartis bought stake in Roche Holding.

Aventis, with 2002 sales of $18 billion:

• Rorer merged with Rhone-Poulenc in 1990 to become Rhone-Poulenc Rorer.
• Fisons merged with Rhone-Poulenc Rorer in 1995 to become Rhone-Poulenc Rorer.
• Possibly an error in the graph: Rhone-Poulenc merged with Rhone-Poulenc Rorer in 1997 to become Rhone-Poulenc.
• Hoechst merged with Marion Merrell Dow in 1995 to become Hoechst.
• Rhone-Poulenc merged with Hoechst in 1999 to become Aventis.

Wyeth, with 2002 sales of $14 billion:

• In 1991, American Home Products buys 60% stake in Genetics Institute.
• American Cyanamid merged with American Home Products in 1994 to become American Home Products.
• American Home Products merged with Genetics Institute in 1996 to become American Home Products.
• No explanation how American Home Products became Wyeth.