Going to feature this post as even though its not the most scientific of explanations, its an every day problem in pharmacy.
PSA For addicts or friends of addicts, most states allow standing order protocols for Narcan. This means that you can usually ask the pharmacist at any pharmacy for narcan and they can using a standing order to bill against your insurance. You never know when you might need it and not have it. Family in from out of town? Didn't know grandma takes 6 Norco a day for the cancer and doesn't appear to be breathing after her ambien? You won't have time to run to the pharmacy.