I take Effexor and it has the same side effect. The excessive sweating is real- I lost six pounds during a twelve mile run yesterday. So I am pretty religious about weighing in before and after runs to ensure that I’m consuming 16-20 ounces of fluid per pound lost to replace. I also get night sweats from time to time, so I tend to weigh myself on those mornings to see roughly how much fluid I’ve lost and replace accordingly. I also take no cal electrolyte drink with me on runs over ten miles with a hand bottle that I can refill along the route if needed. Lastly, I supplement with zinc (in addition to the K, Na, Mg I get in my electrolyte or recovery drink) because it’s lost in sweat and plays a role in overall immunity. I am 100% serious when I say that the struggle to stay hydrated is real. I highly recommend that you do a Levelen sweat rate and composition analysis as well to see what you’re up against. I don’t race tris anymore, but I have been able to go 4:13 for 70.3 while taking Effexor in hot and humid conditions. Hope this helps and I wish you the best of luck!