Sometimes when you try to use an item nothing happens. So if you try to use it again a message "you already using something" will pop up, just like you've been using the item. At least for now if you try to use it again in a short time you'll be sucessful...

This can be a problem if you're bleeding and you try to stop it by using a bandage. In the screenshot added to this post I was trying to drink water from the canteen. {F28837}