This is something I’m consulting with my doctor about, but I’m a bit nervous about this and am wondering if anyone has any experience – I don’t expect medical advice from the forum nor am I planning on ignoring the actual medical advice I receive. 
I’m supposed to be switching my medication (anti-psychotic) from Seroquel to Ziprasidone (brand name Geodon in the States), in part so that I will be able to do stuff like wake up in the mornings and maybe even go for a run before work. While Ziprasidone can be sedating, it’s not supposed to be nearly as bad as some of the other anti-psychotics and Seroquel in particular.
My psychopharmacologist agreed it would be a good fit.
However, I’m worried he skipped over the ‘I’m a runner’ part, b/c in reading more about the drug, I’ve found that it can screw up the QT interval and can cause long QT syndrome (http://www.mayoclinic.com/health/long-qt-syndrome/ds00434). As far as I know, I have absolutely no predisposition to this or anything. But, I’ve read that if you’re on Ziprasidone you should avoid strenuous exercise and be careful of dehydration, in part because of the QT interval problem. I’ve emailed my doctor to ask if that’s one of those warnings they stick up, just because, or if it’s actually something that I should be concerned about. While I realize that death is unlikely, even fainting isn’t something I want to be doing.
My understanding is that it is 1/1500 that Ziprasidone will cause long QT syndrome. But will exercising make me more likely to be that 1 out of 1500?
Of everything I’ve found, this article I think has the best description of how dehydration works to screw up the QT interval: http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=1163276
“Depolarization of the ventricle is primarily due to rapid influx of sodium ions through sodium channels, and its duration is represented electrocardiographically by the QRS interval. Repolarization, the duration of which is represented by the ST segment, involves sodium, potassium, and calcium channels. Although altering either of these components can yield arrhythmias, some antipsychotic medications prolong the QT interval through their effects on repolarization.6 More specifically, it is through a potassium channel that drug-induced QT prolongation is achieved. This potassium channel is the potassium rectifier channel (I Kr).7 Therefore, drugs that block the I Kr channel can induce QT prolongation and subsequent sudden cardiac death from torsades de pointes in otherwise healthy patients.”
My concern is, I can be very careful of hydration, but you’re never going (I don’t think) to not get dehydrated to some degree while working out.
Does anyone have any experience with taking medication that can prolong the QT interval? If so, how did you work the hydration issues? Was there an electrolyte replacer you found particularly good, especially with regards to potassium?