Upon death enemies are not dropping their picked items

I did notice that after I killed a guy who picked up a Grenade or a Stamina Potion, he didn't drop any of both.

Another thing is, if you're full of items, what about make the stamina potion auto-usable when you pick it up? (maybe same for the yellow potion) Because if i'm out of stamina and I don't have any free slot and I pick up a stamina potion, nothing happens, the potion just dissapears, I think it would be nice if it could be auto-used.