Page 92 - JSOM Winter 2017

will not reverse the effects of nonopioid drugs, it also causes when naloxone is dispersed into the nasal cavity as a concen-
no adverse effects when administered with other nonopioid trated fine particulate spray (e.g., mist or aerosol). This is
48
drug exposures. For scent detection canines, it is currently un- best accomplished by either administering the naloxone inject-
known what short- or long-term effect, if any, IN naloxone able solution through a nasal atomization device (Teleflex,
b
has on canine olfaction. Considering its wide margin of safety Morrisville, NC) or via a commercialized naloxone nasal
and relative lack of adverse effects in the face of other illicit spray device (Adapt Pharma, Inc., Radnor, PA). Simply squirt-
a
drugs, when in doubt, it is best to administer naloxone. ing an injectable aqueous solution into the nasal cavity via a
syringe results in loss of a significant portion of the drug due
to drainage (run-off) into the nasopharynx or externally from
Recommended Route for
Naloxone Administration in an OpK9 the nasal cavity. Pathologic conditions (e.g., allergic rhinitis,
epistaxis, physical obstructions, nasal trauma, alterations in
Naloxone is available as injectable, IN, and autoinjector prod- nasal mucus production) and concurrent use of other IN medi-
ucts (see link for “Naloxone Product Chart” under Recom- cations or drugs (cocaine) that alter nasal physiology may sig-
mended Internet Resources). In people, naloxone is approved nificantly impair IN naloxone absorption and bioavailability. 48
for IV, IM, and SC administration, with IV being the recom-
mended route. In canines, naloxone is recommended for IV, Risk to Personnel Handling a Potentially Exposed
48
intraosseous (IO), IM, or SC administration. Naloxone is and Contaminated OpK9
49
only minimally absorbed when given orally due to first pass
metabolism; therefore, per os (PO) remains an ineffective A contaminated OpK9 poses a significant threat for cross-
route of administration. 32,49 In people, per rectum (PR) bio- contamination and self-exposure to OpK9 handlers and first
availability is 15%, whereas OTM administration has shown responders. Personnel must take appropriate personal pro-
to have a high bioavailability (≥70%) in people and rats ; no tective actions and don personal protective equipment (PPE)
52
data evaluating PR or OTM naloxone in canines are currently when handling an exposed OpK9. At minimum, individual
available. IV and IO routes provide the fastest onset of ac- PPE includes: nitrile gloves, N-95 dust masks, eye protection,
tion (1–2 minutes) with the greatest bioavailability (100%) ; and long sleeves; paper coveralls and shoe covers are addi-
49
IM has an onset of action of approximately 5 to 10 minutes. tional items to have on hand. For further information regard-
Following a single dose (5-fold overdose) of transdermal fen- ing human personal protection measures, refer to guidelines
tanyl, IM naloxone at 0.04mg/kg and 0.16mg/kg were both provided by the US Drug Enforcement Administration and
effective at reversing clinical manifestations caused by the Interagency Board (see “Recommended Internet Resources”).
opioid-induced overdose with the 0.16mg⁄kg dose being most Table 2 provides information that handlers and first respond-
effective. Subcutaneous administration is expected to have a ers should consider to help prepare for handling potential opi-
30
slower onset of action as compared with IM. 49 oid exposures in canines.
IN naloxone has been successfully used to reverse opioid over- Table 2 Preparation Measures for OpK9 Handlers and First
dose in people with a very fast absorption rate. 53–55 Because IN Responders
preparations eliminate the risk of contaminated needle stick 1. Have appropriate PPE on hand at all times (See Recommended
and sharps hazard in people, many law enforcement officers Internet Resources).
and other first responders are now being equipped with IN 2. Perform an OpK9 Medical Threat Assessment before training
events and real-world missions:
naloxone products. Interestingly, biopharmaceutics and clini- a. Identify local veterinary resources available in the area of
cal pharmacokintics relating to IN naloxone in people are operations.
sparse, controversial, and not completely known. One study ii. Hours of operations
reported a ≤4% bioavailability for IN naloxone. This study iii. Staffing, medical and equipment resources
56
iv. Establish line of communications and rapport
may be misleading as it used a potentially inferior delivery sys- b. Identify evacuation and transport routes.
tem and nonoptimal solution concentration. 48 c. Identify logistical evacuation assets (vehicle, air ambulance,
other).
Due to its demonstrated clinical effectiveness for treating opi- 3. Receive training in the following:
oid overdoses, 53–55 availability among first responders, nonin- a. Identifying opioid toxicity in K9s.
b. Proper use and administration of naloxone.
vasive intervention, and user-friendly technique, IN naloxone c. Basic K9 life support measures (e.g., rescue breathing with bag-
is an option for exposed OpK9s as well. Scientific evidence valve-mask, chest compressions).
evaluating IN naloxone in canines is limited. The pharmaco- 4. Keep important veterinary contact information on hand:
kinetics of IN naloxone have only been evaluated in one small o Primary veterinarian’s or local 24/7 emergency veterinary
hospital phone number
study involving healthy canines in which the reported bio- o ASPCA Animal Poison Control Center (APCC): 1-888-426-4435
availability of an 8mg/100μL nasal spray was 87.88%. The o Pet Poison Hotline (PPH): 1-855-764-7661
38
University of Pennsylvania Working Dog Center is currently NOTE: A nominal one-time fee may be charged when calling the
engaged in a Department of Homeland Security–funded study APCC and PPH helplines.
evaluating the pharmacokinetics/pharmacodynamics, safety,
and clinical efficacy of a 4mg IN naloxone spray in canines. a
Summary
The method of administration, formulation used, and exist- Operational K9s of all discipline (detection, apprehension,
ing pathologic conditons may affect IN naloxone absorption. SAR) are at risk for illicit opioid exposure and subsequent
IN absorption and bioavailability are probably best enhanced toxicity. Considering their contribution as a force multiplier
a Narcan , Adapt Pharma, Inc. Radnor, PA. (https://www.narcan.com/)
®
™
b MAD Nasal Intranasal Mucosal Atomization Device. Teleflex. Morrisville, NC. (http://www.teleflex.com/usa/product-areas/anesthesia/
atomization/mad-nasal-device/)
90 | JSOM Volume 17, Edition 4/Winter 2017