I wrote about this as one of the Five Easy Lies. And now, courtesy of the blog Pharma Analysis, I can show a real-life example.

Imagine a drug company marketing an opiate on the basis that it has a long half-life. This is a major selling point because most existing opiates lose effect after 3-6 hours, resulting in breakthrough pain. If a drug can provide a more lasting effect, this would be a huge competitive advantage. The drug company is Purdue Pharma. The drug is Oxycontin.

Sounds good, right? But Purdue’s success story has just turned very, very sour as Purdue has agreed to a US$ 634 million settlement for misleading marketing. While there is a lot more to the case than a single graph, this sums it up beautifully:

This is the graph Purdue used in its marketing. You may notice that the y-axis is a log scale. Clinicians and people using opiates are not interested in a log-scale for blood levels of a drug because it compresses a ten-fold difference in concentration into a single unit difference in graph height. If you graph it in a way that is meaningful, you would use a linear scale. And this is what it would look like:

The story gets better here. This reminds me that I’ve been meaning to post my own example of recent dubious drug marketing — an example I use in my teaching. Soon, I promise.

Hat tip to Bad Science.

Tags: five easy lies, log, logarithms, oxycontin, purdue