Naloxone is a medication used to reverse opioid overdose rapidly. It works by rapidly binding to the same receptors in the brain as opioids, such as heroin, morphine, and fentanyl, and reversing their effects, including depression of the respiratory system. Naloxone is often used by emergency medical personnel, such as paramedics, to revive individuals who have stopped breathing due to an opioid overdose. It can also be used by family members, friends, or bystanders of someone at risk of an overdose. Naloxone is typically given as an injection or nasal spray and can be a life-saving intervention for an opioid overdose. In some countries, naloxone is available without a prescription in community pharmacies, allowing people at risk of an overdose or their loved ones to access the medication in emergencies.