I have gotten the sweats from some meds, but
for me it was all over
sweats, not just the feet. Now, the callouses? No. Not the drug. Not sweating. What it can cause is fungal infections if it's constant, but you don't mention those. Buy any new shoes lately? New socks? If it is the drug, and it's working well for you, this probably isn't enough of a problem to stop taking it for. If it's not really working, then it might be.