Why Intranasal Administration?
Intranasal (IN) medication administration delivers drugs through the nasal mucosa using a mucosal atomizer device (MAD). The nasal mucosa has a rich blood supply and allows rapid absorption into the systemic circulation, bypassing the gastrointestinal tract. In EMS, the IN route offers a needle-free alternative for patients without IV access, providing a faster onset than oral or intramuscular routes for many medications.
Advantages of Intranasal Delivery
- No needles required, reducing sharps injury risk and patient anxiety
- Rapid onset (typically 3 to 5 minutes for most medications)
- Easy to administer in moving ambulances or austere environments
- Useful for combative or seizing patients where IV access is not feasible
- Effective in pediatric patients who fear needles
- Can be administered by BLS providers in some systems
Common Intranasal Medications in EMS
Naloxone (Narcan)
IN naloxone at 2 to 4 mg is widely used by both BLS and ALS providers for suspected opioid overdose. It has comparable efficacy to IV naloxone for reversing respiratory depression. Administer half the dose in each nostril to maximize mucosal contact.
Midazolam (Versed)
IN midazolam at 0.2 mg/kg (up to 10 mg) is effective for active seizures when IV access is not available. Studies show it terminates seizures as effectively as IV diazepam when the time to establish IV access is accounted for.
Fentanyl
IN fentanyl at 1.5 mcg/kg provides rapid pain relief without the need for IV access. It is particularly useful for pediatric patients and for patients with difficult IV access.
Ketamine
IN ketamine at 0.5 to 1 mg/kg provides sub-dissociative analgesia through a non-invasive route.
Technique and Limitations
Proper technique is essential for effective IN delivery. Use a MAD device attached to a syringe. Insert the tip just inside the nostril and deliver the medication as a fine mist. The maximum volume per nostril is 1 mL in adults and 0.5 mL in children. Larger volumes run out of the nose or drain into the pharynx, reducing absorption. If the total dose requires more than 1 mL per nostril, split the dose between both nostrils or use an alternative route.
IN delivery is ineffective in patients with significant nasal congestion, nasal trauma, or active epistaxis. Cocaine or vasoconstrictive nasal spray use can reduce mucosal blood flow and impair absorption. Always have an alternative route available if the IN route proves inadequate.