Pyrimethamine and the Market

The latest controversy in the world of infectious disease is the price increase of the drug pyrimethamine, the primary component of the treatment of the parasitic disease Toxoplasmosis. Toxoplasmosis is a ubiquitous infection which, for most people, causes mild to no symptoms. It is acquired by eating undercooked meat or ingesting the cysts shed by cats. It is really a fascinating disease that is responsible for changing the behavior of infected rats, making them less afraid of cats--the ultimate destination of the parasite. It is estimated that 11% of the US population is infected.

The parasite causes problems, like many microbes, in those that are immunosuppressed. Those with AIDS and a CD4 count less than 100 are particularly prone to developing a brain infection with the parasites as are newborns borne to infected mothers, transplant patients, and others with immuno-suppressing conditions. 

Pyrimethamine is a drug that was initially FDA approved in 1953 and is no longer under patent, meaning any company is free to manufacture it. The fact is, however, that there is currently one US approved manufacturer who recently increased prices substantially. This has provoked a heated societal debate regarding drug prices. 

I have a few thoughts about this event (similar to those I have regarding hepatitis C medications) which many in my field no doubt disagree with but I think they are worth contemplating even if it changes no one's mind. As an infectious disease physician, who has taken care of several patients with toxoplasmosis, I don't want to see toxoplasmosis morbidity and mortality rise but pyrimethamine, in its current formulation, is the property of Turing Pharmaceuticals which has the right to set the price wherever they choose. I do not believe that anyone has a right to this product and strongly oppose any effort to expropriate or set price controls on this, or any other medication. While I have no understanding of how the new price was determined, it will eventually have to withstand the scrutiny of the market. If the price is set higher than the market will bear, because it is no longer under patent, other manufacturers will enter the market lowering prices. Ideally this would happen near instantaneously but, because of legislative barriers to entry, which include a multi-step approval process, it will take some time. Better alternatives to the current regimen may also appear in time as well.

Overall, however, infectious disease products have become less attractive to pharmaceutical companies and this, at root, is why we are left with just one manufacturer for many important non-patented products. The disincentives to enter this market are myriad and the ultimate answer to this scenario is not more intervention but to remove artificial barriers to entry, inviting the appearance of competitors in the market. The anger directed at Turing would be better employed if used to facilitate dynamism in the infectious disease market--it's the only long term solution.