Which route is naloxone NOT effective when administered?

Naloxone is a medication used to reverse opioid overdoses, and its effectiveness can vary depending on the administration route. When naloxone is administered via the endotracheal tube (ETT), its absorption and bioavailability are significantly decreased compared to other routes. This is primarily because the medication is not designed for effective absorption through the respiratory tract in that manner. While ETT can technically be utilized for drug administration in some emergencies, it is not the preferred method for naloxone, as the effectiveness may not be reliable.

In contrast, when naloxone is given intravenously (IV), intramuscularly (IM), or intranasally (IN), it is rapidly absorbed into the bloodstream and works quickly to reverse the effects of opioids. Each of these routes allows for adequate systemic circulation of the drug, ensuring its therapeutic effects are realized more consistently and reliably than via ETT.