Naloxone can be absorbed through several routes, including intravenous (IV) injection, intramuscular (IM) injection, subcutaneous injection, nasal administration, and inhalation. The specific absorption rate and onset of action can vary depending on the route of administration.
When administered intravenously, naloxone typically takes effect within 2 minutes and has a rapid onset of action. When administered intramuscularly or subcutaneously, it can take 5 to 15 minutes for the effects to begin. Nasal administration of naloxone can take 2 to 5 minutes for the effects to begin, and the duration of action is generally shorter compared to IV or IM administration. Inhalation of naloxone through a device such as a nebulizer or atomizer can also be effective, although this method is less commonly used.
Regardless of the method of administration, naloxone works by binding to opioid receptors in the brain and reversing the effects of opioids, including respiratory depression, sedation, and analgesia. It is commonly used in emergency situations to rapidly reverse the effects of an opioid overdose.