Technically speaking, no, Narcan is not going to harm someone in cardiac arrest in and of itself. However, we also know that the interventions that are most likely to save someone in cardiac arrest are: early defibrillation and high-quality chest compressions. The more interventions and medications we add to our cardiac arrest care, the less we focus on the things that matter most. Furthermore, Narcan does not take effect immediately. In a patient who has become so hypoxic from their opioid overdose that they have suffered a cardiac arrest, the treatment they need is active oxygenation/ventilation with an iGel or ETT. Narcan alone will not be enough to reverse this person’s hypoxia and cardiac arrest, but active airway management will. If these patients eventually get Narcan, great, but we don’t want administration of Narcan to take priority over active ventilation as this is what ultimately gives us the best shot at achieving ROSC, not the administration of Narcan itself.