hyperhidrosis
"I have suffered with severe hyperhidrosis (palmar, plantar, and axillary) since birth and was diagnosed at a very young age when I broke out with a heat rash all over my hands and feet.  Thankfully, I have outgrew the rashes but unfortunately not the sweat.  I have tried Drysol, Iontophoresis, Botox injections, Glycopyrrolate, and Oxybutynin (as well as extended release versions of the last two medications).  I feel safe to say that two 5mg tabs of Oxybutynin at nighttime has worked best for me.  I have been taking Oxybutynin since 2005--nearly 10 years now and it still is holding up pretty well.  Side effects that I experience: dehydration, dizziness and weakness."