Opioid drugs work by acting on specific receptors found in the brain and nervous system. When these drugs attach to those receptors, they reduce the amount of pain felt. Taking too many opioids can lead to an overdose and that can stop someone from breathing. The person may also experience other symptoms. NARCAN^® Nasal Spray stops the opioids from being attached to the receptors, and this reverses the effects and symptoms of the overdose.