Outpatient Pain Control Flashcards
What category of drugs has the best evidence to support use in domestic species as an analgesic?
NSAIDs
How does grapiprant differ from NSAIDs in its mechanism of action?
Instead of targeting the production of a prostaglandin, grapiprant is an EP4 receptor antagonist
What are the “ramp up” times for dogs and cats, respectively, when using the transdermal fentanyl patch?
12 hours in dogs
24 hours in cats
Since fentanyl has a very high first-pass effect, why would accidental ingestion of a fentanyl patch pose a problem to a child?
Small children will chew on it and it will be absorbed transbuccally, which will cause the child to die. The first-pass effect only occurs once it’s swallowed, but the child chewing on it will cause it to act quicker and in the mouth
Unlike in man, oral extended-release morphine is not typically used in dogs. Why?
Oral bioavailability is low and the variable absorption limits clinical usefulness
What are the conditions of the Recuvyra® RiskMAP?
A single dose (2.7 ml/kg) applied to the skin of dogs prior to surgery controls pain for at least 4 days
Apply 2-4 hours prior to surgery
Dog restrained for a full 2 minutes and avoid contact with the application site for 5 minutes to allow compete drying
Dog should be isolated from children for 72 hours
In addition to NSAIDs, name the drugs that can be used to manage moderate pain in cats as outpatients.
Buprenorphine
Tramadol orally as a suspension
Gabapentin
Name the oral medications used in dogs when transitioning from injectable opioids
Tylenol 3 and 4 Lortab NSAIDs Galliprant Tramadol
Describe tylenol number 3 (acetaminophen and codeine)
Typically has 325 mg of acetaminophen per tablet (some have 500 mg) and 30 mg codeine
Dog generates very little morphine. Codeine appears a good analgesic but no hard data
Class 3 controlled drug
Describe Lortab (acetaminophen and hydrocodone)
Hydrocodone at 5, 7.5, or 10 mg per tablet
Acetaminophen content can be either 325 or 500 mg per tablet
Acetaminophen is used to limit abuse
Hydrocodone is active itself but is also metabolized to active metabolite hydromorphone. This conversion is limited in dogs
Class 2 controlled drug
Describe Perococet (acetaminophen and oxycodone)
Low bioavailability and erratic absorption appear to limit use in small animals
Needs to be dosed every 6 hours
Doesn’t really have an advantage, so it’s not really used in vet med
Class 2 controlled drug
Describe sustained release oral morphine
Oral bioavailability is low
Variable absorption limits clinical usefulness
Class 2 controlled drug
How does tramadol work and why is its efficacy controversial in dogs? How does the cat differ?
Tramadol provides analgesia mainly due to its active metabolite, M1
The dog produces a limited amount of the active metabolite
The efficacy is unclear because:
One RCT in dogs with natural OA demonstrated a benefit at 4 mg/kg tid
Two RCT in dogs and 2 pain models failed to differentiate it from placebo
Cats produce substantially more of the active metabolite than dogs
Efficacy:
Provided analgesia in post-op gonadectomy and in thermal-threshold model (oral)
In one study of 15 cats with OA, tramadol-meloxicam combination provided no evident benefit over meloxicam alone
If used in dogs, why is tramadol probably not appropriate for long-term administration?
The active metabolite is an autoinducer, promoting its own elimination. After 10-14 days, the concentrations of the active metabolite (M1) are decreased and dogs have undetectable MI at 3 weeks
What advantage does a xylazine epidural have over a lidocaine epidural in cows?
You don’t have to worry about making them accidentally lie down because it doesn’t anesthetize them, just analgesia. Some sedation is seen
What anticonvulsant is used to manage neuropathic pain and Feline Hyperesthesia Syndrome?
Gabapentin
What NSAIDs can be used long-term in cats?
Aspirin if pain is mild and somatic
Meloxicam “against label use”
Piroxicam
Robenacoxib
What topical analgesics are often used in horses?
NSAID diclofenac topical (Surpass)
DMSO
Discuss the pros and cons of continuous perineural nerve blocks (CPNB) in horses.
Pros:
Good at controlling pain in the feet and joints that we can’t control otherwise
From a journal article: catheters can be left safely in place for up to 10 days without major side effects and complications
Apparently, Dr. Fontenot said that whoever said this is very optimistic
Cons:
Technically challenging to place and maintain catheter
Discuss the pros and cons of ammonium sulfate nerve blocks (CPNB) in horses.
Pros:
This will stop transmission in the C fibers, which tend to carry chronic and aching source of pain
Cons:
Won’t help with a severe laceration because that pain is controlled by Aδ fibers that ammonium sulfate doesn’t work on
Not a complete anesthetic, so it can be hard to evaluate
Why are fentanyl transdermal patches not commonly used in horses?
It’s subtherapeutic in 1/3 of horses and you can’t predict which 1/3 it could be
When might an alcohol epidural be used in a cow and what are its pros and cons?
This is used as a last resort
This is considered a permanent epidural and you need to be extra careful to not give a high epidural or you may cause paralysis
The owner needs to understand that this is permanent. The cow will have no control over its tail, so hygiene will become a concern. This is usually a salvage procedure.
Outside of the epidural space can cause the sloughing of the tail head
