The intranasal drug route is more than just an administration route. There are unique benefits for IN delivery. The anatomy of the nasal mucosa allows for rapid drug absorption, and its location allows drugs to be delivered directly into the bloodstream and bypass the blood-brain barrier, all without the need for establishing IV access. Bypassing the blood-brain barrier allows many drugs to more rapidly benefit the patient by speeding their action on the central nervous system. This is particularly beneficial when administering benzodiazepines for patients experiencing seizures.
Another benefit of the route is its safety. No needles are needed, such as with IV, subcutaneous and intramuscular drug delivery. The absence of needles increases provider safety, particularly when the need arises to administer drugs to combative or seizing patients. Eliminating needles decreases the chances of accidental needlesticks both on scene and while managing patients during transport.
The disadvantage to intranasal drug delivery is that a limited number of drugs can be delivered to the nasal mucosa. Not every drug used by prehospital providers can be atomized for absorption and provide the same intended effects. Additionally, patients with diseased or unhealthy nasal mucosa, such as from long-term drug abuse or cancer, will likely have impaired drug absorption, as their turbinates can be destroyed or damaged from disease processes. Foreign debris, such as blood and other fluids in the nasal cavity, can also impair drug absorption.
Intranasal drug administration has a variety of beneficial prehospital indications, including pain management, seizure control, narcotic drug reversal and hypoglycemia management.
A great deal of research has demonstrated that pain control can be obtained through intranasal drug administration in a safe and effective manner with few side-effects.2 There are a variety of different pain medication choices, including opiates and nonsteroidal antiinflammatory drugs that provide analgesia and can be administered intranasally.
One of the most serious concerns with opiate drug administration is the potential for significant respiratory depression leading to hypoxia. However, the slower absorption of IN drugs, compared to IV administration, is enough of a delay that the risk of respiratory depression decreases significantly. When a drug is administered at the recommended intranasal dose, which is 1.5–2 times the IV dose, respiratory depression does not occur.3,4 Additionally, despite the slower absorption rate, the time saved by eliminating the need for IV access actually allows for the patient to experience a drug’s effects faster.5
Recently, ketorolac (Toradol) was FDA-approved for intranasal administration. Ketorolac is a nonsteroidal antiinflammatory drug that is effective in managing short-term moderate and severe pain. When given via IV, it has near-immediate onset, with full effect reached in 20–45 minutes, and has a half-life of 6–8 hours. When administered intranasally, ketorolac has the same onset and half-life. In one study, ketorolac was found to reduce the need for opiate analgesia when 30 mg was administered intranasally.6 This represents great potential benefit for EMS providers. Since ketorolac does not have any of the side-effects opiate drugs have, including hypotension and potential respiratory depression, it may be a reasonable drug for basic and intermediate life support providers to administer intranasally. By decreasing the number of patients requiring opiates for analgesia, fewer patients require intravenous access for analgesia, and fewer needles means increased safety. Ketorolac also does not have the addictive property of opioids, which decreases the potential for provider theft and misuse.
Fentanyl is a synthetic opioid analgesic that has a shorter duration and half-life than morphine. It is associated with less cardiac instability than morphine, but otherwise functions similarly and has effects on the body nearly identical to morphine and is effective in treating moderate to severe pain. The typical IN dose for fentanyl is 2–4 micrograms per kilogram. Remember, intranasal doses are 1.5–2 times normal doses.