On being an outlier

by Michael Tobis     Department: Health & Life Sciences

Some people can't abide broccoli. Myself, I cannot swallow a brussels sprout. (Fortunately that doesn't come up as often as broccoli does.)

I once got a case of pancreatitis for which my only risk factor was a common antibiotic, erithromycin. I told my good friend GW, a dermatologist about this and he found it well-nigh unbelievable. He has prescribed erithromycin a thousand times without seeing this reaction. It's rare.

When I found myself having trouble staying awake or concentrating recently, I had a lot of difficulty identifying why. About a week ago, after having forgotten my medications for a few days while traveling, I started up again. I was hit by an amazing bout of sleepiness ("somnolence" the MDs call it). I finally came round to suspecting the new drug I had been prescribed for allergies, montelukast sodium, (trademarked as Singulair), and quit using it. I am still a bit sleepy but my mind is firing on all cylinders. Given what I do for a living you can imagine my relief.

Based on my erithromycin experience, I was willing to take myself for an outlier and leave it at that, but my perspective was dramatically altered a few days later when news came out that Singulair is possibly involved in increased prevalence of suicide. You really don't expect your replacement for over-the-counter allergy medications to be mind-altering to such a severe extent as to measurably change the risk of suicide.

The coincidence makes me wonder if I'm that much of an outlier on this. The medication certainly seems to change the way my neurological system works quite dramatically. There was enough delay and it was sufficiently sporadic that it was hard to make the association, which is why I was taking it on and off for almost a year. Looking back, I did have a pretty severe bout of depression a couple of months after I started.

None of this proves anything about the utility of the medicine. I understand that. I am not asking my MD friend to stop prescribing erithromycin.

I understand that many people find Singulair very valuable, as well. Surely it passed rigorous clinical trials where cognitive and emotional function were tested along with everything else. This would tend to indicate that my experience is rare.

There are dozens of people complaining about Singulair on the net nowadays (many of them parents of young asthmatic children), but that doesn't prove very much either, as there have been millions of people for whom it was prescribed. Seeing all these stories is a bit overwhelming, but it doesn't prove anything.

Nevertheless, I did report my experience to the FDA.

One possibility to consider is that the quality control on the manufactured drug is not as good as it was on the drug distributed for clinical trials. There's no clear way for me to distinguish between the two very unlikely events 1) I happen to be among the outliers neurologically sensitive to this drug or 2) for some reason a drug with mind-altering properties has passed muster as a treatment for minor chronic respiratory problems.

Before the news stories, I believed the first, and after them I have trouble dismissing the second possibility. It's not logically clear that the news story should have changed my opinion very much, but it certainly changed my attitude. How you see the world depends on where you see it from.

We need to be very careful in jumping to conclusions. I would be very interested to hear from users of Singulair who have experienced no evidence of significant changes of alertness or mood associated with the medicine. If it's hard to round them up that would certainly be a matter of interest. I still don't have enough evidence to conclude how common this sort of thing is. I will follow this story with considerable interest.

One thing I do conclude from this experience is that the probability of side effects should be explicitly provided with any medical treatment. People should have the ability to make rational decisions on maximum information. A list of side effects is not sufficient; some indication of likelihood is needed.

Tags: medicine, side effect

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