I would say carrying a life-saving antidote would be good. You can save someone's life!
However, addiction is a problem in any form. Unfortunately, the bad thing is just that drugs are expensive and lead to another behaviour as stated. I don't know if alcoholism is as widely covered?
Anyway, I have heard that a lot of the recent opioid addiction can stem from the healthcare system in the sense that a painkiller prescription is often cheaper than physiotherapy or other treatments and is therefore widely used. Then prescription drug abuse starts, then people move to heavier stuff and so on. I have also read up on how many overdoses happen after rehab when a person's tolerance has lowered and they re-dose with the same volume as before and BAM they're out.
Should we go Duterte and simply erase dealers? Go Portugal and legalise everything which has apparently reduced abuse significantly? Should we follow trials of some countries where addicts swap their street drugs for a clean alternative in monitored area with medical and rehab staff at hand?
The deeper issue is still there, but maybe a Narcan dose can help save a life in the meantime.