The medication that you're referring to, Chantix, has been associated with a lot of neuropsychiatric side effects; another one, Zyban, or Wellbutrin, much less so. I don't prescribe Chantix to my psychiatric patients because they're coming to me because they have suicidal thoughts and ideation.
Going back to your other question, are there other medications that have this many side effects, if you look at the medications that are the top 10 in side effects, and neuropsychiatric side effects, just about all of them are psychotropic drugs, they are antipsychotic medications or antidepressant medications or medications for bipolar disorder or seizures, which are often the same. So mefloquine is up there. I think if we had any other medication that caused this many side effects, it would have been pulled from the market a long time ago.
One historical piece that we did not mention is that mefloquine, which was developed by the Army and Hoffmann-Laroche, did not have post-marketing surveillance, by that I mean after it was put on the market nobody was gathering the side effects, unlike other medications that were done in a more conventional way. That is part of the problem here, and Dr. Nevin can elaborate on that.
One other piece I wanted to mention that I think is very important is we've briefly said this drug causes toxicity in the brain stem and in the limbic system. We see that when we look at rats and chop off their heads and look at their slices. They have vacuoles, places where the mefloquine has poisoned the brain stem, and the brain stem is what causes your balance. The problem with it is the dizziness, the nystagmus. Dr. Nevin mentioned the limbic system. The limbic system is where our emotions are, that lead to the amygdala, which is affected by post-traumatic stress disorder. The hypothesis—again, not proven—is that these changes to the limbic system are what leads to this intense aggressiveness and anger, and that's what I think makes this medication so dangerous.
Why do some people react to it and some not? It could be genetics. A theory of mine is that in Somalia it was very hard to get hydrated, to get enough water. That was a very primitive environment. I remember the truckloads of water that we'd all be scrounging for. It was hot and people didn't drink enough. I think the damage to the veterans in Somalia was greater than, say, to those in Iraq or Afghanistan, where there was a mature theatre and people got more water. Again, that's a hypothesis. Another piece is that some people have changes in the blood-brain barrier. They metabolize agents more. It is clear that while some people are severely affected, others are not affected at all, and that's led to some of the questions of, this is just an hysterical reaction on the part of the journalist, because I took mefloquine and I was okay. I did take mefloquine and I was okay, but I was also in a medical unit, so could get water. I'd be curious about Claude's experience, whether he was able to stay hydrated. Similarly with the Canadian Airborne Regiment, I believe they were in primitive conditions.
Finally, what I often see with mefloquine is it's the straw that breaks the camel's back. You're in nasty, difficult circumstances, you are irritable, the food sucks, the water sucks, there's not a place that you can go, excuse my language, and take a dump so you're irritated about that, your wife is going to leave you. But then you have this pill on top of that that just revs up your rage, and you hear it over and over again, and you have these crazy bad dreams, these vivid dreams, nightmares, and you just snap.