People who are dependent on opiates and opioids.
Some people who are in a lot of pain legitimately need the medicine in order to have a normal life. It doesn't make us high, it makes us 'normal' because we actually require the medicine to bring us to normal levels of activity.
Just because someone is physically dependent on the medicine, does not make them an addict too
Most of us would rather never take another pill in our lives if we were suddenly healed.