*Opiate drugs have a chemical structure that's very similar to your body's natural feel-good chemicals, endorphins. This allows them to partake of the endorphin receptors and ultimately overtake their place in your body.
Like an evil twin, the drug's molecules lock onto the endorphin-receptor sites on nerve endings in the brain and begins the succession of events that leads to euphoria and/or analgesia.*
Like a fake endorphin high. Sorry about your foot...there's nothing worse than being in pain...and off balance. Be careful!