Naloxone, also known as Narcan, is an opioid reversal or opioid antagonist medication given to patients experiencing opioid overdose. Its route of administration is often IM, IV, subcutaneously, or nasally for patients that are unconscious and unresponsive. If the patient is responsive, they likely will not need this agent and can, instead, simply be transported to emergency services if there is concern over the amount of drug consumed. If the first dose of naloxone seems ineffective after 2-5 minutes, a second dose can and should be administered.
CPR should not be optional if a patient needs CPR. If the patient is experiencing an overdose and an initial dose of naloxone has been administered, if they are still breathing and have a pulse, CPR is not required. If they are unresponsive with no breathing or pulse as a result of an overdose, CPR is not a choice -- it must be performed and the naloxone also administered. If the patient is unresponsive with no breathing or pulse and you are unaware if it is the result of an overdose, giving the initial and secondary doses of naloxone will not harm the patient; neglecting to perform CPR will. The takeaway here is Narcan is NOT a substitute for chest compressions and rescue breaths if the patient needs CPR!
If the patient becomes responsive after receiving a first dose, the second dose will not be necessary. Just like performing CPR, if the person becomes responsive, they do not need more CPR. However, in both cases they will requires immediate emergency services and monitoring; another dose of naloxone may be possibly be given then if needed.
Lastly, the patient likely will not ask for another dose of naloxone. The medication blocks the effects of the opioid, usually by blocking the receptors they bind to, propelling the patient into withdrawal though free opioid molecules are still in their bloodstream. As a result, they will likely be irritated and combative, not necessarily asking for another dose. In the event that it does occur, you could tell them that no longer need the Narcan, and if they insist you can give them a second dose -- again, the medication is not harmful if given to a person not actively overdosing so if they need a nocebo effect to take place, so be it. This, however, is not an official indication for a second dose of naloxone to be administered.