What can happen during metabolism of a drug?

What can happen is the human body to start reacting very strange and awkward due to the harmful toxins inside a drug, but if it's a MEDICAL drug, the body will start healing and try fighting back the disease or sickness. 
I hope this helps! :-)
If it does, PLEASE choose this answer as the Brainliest once you get the chance! :-)

As long as it was one lick and the dog is a bigger dog, it should be fine. watch it carefully for a few days.