Naloxone is a life-saving medication that's used to reverse the effects of anopioid overdose. This medication can help a person's breathing return to normal in as quickly as2 to 3 minutes. The effects of naloxone only lasts30 to 90 minutes, so it's important for a person who's experiencing an opioid overdose to get medical help right away. Naloxone comes in 2 different forms, a nasal spray (Kloxxado,Narcan, and generic) and auto-injector (Zimhi). You can get naloxonewithout a prescription.