Therapeutic
Intranasal Drug DeliveryIntranasal Pain Medications Overview
Topic summary:
Nasal delivery of pain medication is an attractive form of pain control in settings where patients are suffering severe pain, yet do not have any IV access. Typical situations include hospice care at home, clinic settings where a painful procedure or dressing change is needed, EMS treatment of the injured or burned patient (especially children), Emergency treatment for orthopedic trauma, burns and pediatric painful conditions. There is now extensive literature on this topic (reviewed on this website) showing IN pain control is as effective as IV pain control, faster in onset in the situation where an IV does not already exist, can be titrated, and more commonly given in settings where concerns regarding IV start or IV opiates occur (small children with severe pain). Furthermore, the drugs can be reversed by intranasal naloxone if a problem arises. The most extensively studied intranasal medications are fentanyl and diamorphine. Other moderately well studied medications include sufentanil and ketamine. This overview section provides a quick look at the topic and provides dosing and protocols. Digging deeper behind this page is an extensive review the literature with supporting references (Click here to skip the overview below and to go directly to the deeper discussion).
Key Concepts regarding delivery of any nasal medication to the systemic circulation and brain
Use the right dose!
- Nasal medication doses are NOT equivalent to IV dosing. Using an IV dose will usually fail. (Read about bioavailability in the Overview page)
- A general rule of thumb is you will need twice the IV dose (often times more). This website provides extensive literature to support the doses recommended. Read those studies to assist you will deciding the dose you feel is appropriate for the clinical situation.
- Respiratory depression is rarely a concern with nasally delivered generic concentrations of drugs - so use the right dose. Click here for a brief but more in depth discussion on this concept.
Minimize volume, maximize concentration of the drug
- Use the most concentrated (potent) available formulation
appropriate for the task
- eg: IN fentanyl at 50 mcg/ml is adequate for children with burns and long bone fracture pain, but generic fentanyl is a bit dilute for a 100 kg man. However, generic sufentanil at 50 mcg/ml is 8-10 times more potent and works very well in a 100 kg male with a long bone fracture.
- Do NOT dilute the drug
- 0.2 to 0.3 ml per nostril is an ideal volume in the clinical setting - good coverage but low risk of significant drug loss from delivery error. We push it up to 1 ml/nostril if needed realizing there will be some drug loss.
Large volumes are lost into the pharynx or out the nostril.
Maximize total absorptive surface area
- Use BOTH nostrils for volumes over 0.3 ml. This doubles the absorptive surface area and reduces runoff.
- ABOUT half per nostril is clinically adequate - do not worry about being exact.
Use a delivery system that maximizes mucosal surface area coverage and minimizes loss to the environment and runoff
- Droppers work in research using cooperative patients who hold still for many minutes. They tend to be less effective in clinical trials.
- Atomization (not nebulization over minutes) allows immediate delivery of all the drug directly to the mucosa in a broad area of coverage with little loss to the environment. This improves clinical effect and does not require a cooperative patient.
- Account for device dead space in your dosing calculations especially for children or small drug volumes.
Be thoughtful about anatomic issues and head positioning to enhance delivery
- If the patient is cooperative - Occiput/crown down (neck extended in sitting position) delivers more drug higher onto the turbinate's to enhance absorption and nose-brain transport.
- Blood and mucous should be suctioned if possible to enhance mucosal coverage.
- Use of vasoconstrictors might reduce drug absorption (cocaine, epinephrine, oxymetazoline, phenyephrine)
Key Concepts related to nasally delivered pain medications
Dosing: The dose for nasal drug is higher than IV drug. This occurs because not all the drug is absorbed and that which is absorbed takes longer and peaks at lower levels in the blood stream. See below for doses supported by the literature. Failure to use the adequate dose will likely lead to failure to control pain.
Respiratory depression: Generic fentanyl delivered intranasally does not lead to respiratory depression. Click here for a brief but more in depth discussion on this concept. However, the new highly concentrated patented nasal formulations of fentanyl, and generic sufentanil (already highly concentrated) can cause respiratory depression so require more careful administration.
Nasal burning: The nasal opiates are tolerated very well and do not burn.
Titration: Repeated doses given every 10-15 minutes for the opiates can lead to more titrated effect in essentially the same fashion as is done with IV opiates.
Reversal: An extensive amount of literature exists showing that opiate induced respiratory depression can be reversed with nasal naloxone. that data is available on this website under the opiate overdose tab.
Dosing information and delivery protocol
- Fentanyl - 2 mcg/kg
- Sufentanil - 0.4 to 0.7 mcg/kg (lower dose for elderly, higher for kids)
- Diamorphine - 0.1 mg/kg
- Ketamine - 1 mg/kg (sub-dissociative dose - pain control primarily)
Commonly used generic intranasal medications - single page dosing summary (click here)
In Depth literature review, discussion, bibliography (Click here)