An arrow going from one drug to another means that at least half of the major side effects of the first drug are also major side effects of the second drug. A major side effect is one that requires a patient to visit a doctor immediately. Large scale drug studies can uncover many rare side effects. For this reason I only considered the most common major side effects as defined by Drugs.com. Drugs that don’t share at least 50% of their major side effects with another do not appear on the graph.
I don’t know much about prescription drugs so I’m hoping that someone who knows more will point out some interesting observations that can be obtained from this visualization.
I got a list of the most prescribed drugs from http://www.medscape.com/viewarticle/825053 . In order to get the most common major side effects for each drug I scraped drugs.com. I processed the data using Python and its library Pandas and I used D3.js for the visualization. The resulting data set can be found here.