Safety and efficacy of intranasally administered medications in the emergency department and prehospital settings

Purpose: The safety and efficacy of medications that may be administered via the intranasal route in adult patients in the prehospital and emergency department (ED) settings are reviewed.

Summary: When medications of appropriate molecular character and concentration are delivered intranasally, they are quickly transported across this capillary network and delivered to the systemic circulation, thereby avoiding the absorption-limiting effects of first-pass metabolism. Therapeutic drug concentrations are rapidly attained in the cerebrospinal fluid, making intranasal administration a very effective mode of delivery. To optimize the bioavailability of intranasally administered drugs, providers must minimize the barriers to absorption, minimize the volume by maximizing the concentration, maximize the absorptive surface of the nasal mucosa, and use a delivery system that maximizes drug dispersion and minimizes drug runoff. Medications can be instilled into the nasal cavity with syringes or droppers by applying a few drops at a time or via atomization. The intranasal route of administration may be advantageous for patients who require analgesia, sedation, anxiolysis, termination of seizures, hypoglycemia management, narcotic reversal, and benzodiazepine reversal in the ED or prehospital settings. Medications that have been studied in the adult population include fentanyl, sufentanil, hydromorphone, ketamine, midazolam, haloperidol, naloxone, flumazenil, and glucagon. The available data do indicate, however, that intranasal administration may be a safe, effective, and well tolerated route of administration.

Conclusion: Based on the published literature, intranasal administration of fentanyl, sufentanil, ketamine, hydromorphone, midazolam, haloperidol, naloxone, glucagon, and, in limited cases, flumazenil may be a safe, effective, and well-tolerated alternative to intramuscular or intravenous administration in the prehospital and ED settings.