DM1 Pt7-5 Acute Pain Control - Opioids Flashcards
What are the major classes of analgesic drugs used for acute pain management in cats?
Opioids, NSAIDs, Alpha-2 adrenoreceptor agonists, Ketamine, Local anaesthetics, and Tramadol.
Why are opioids widely used for pain management in cats?
Opioids are used due to their safety, efficacy, ability to be redosed, and their versatility in administration.
What is the role of opioids in peri-operative pain management?
Opioids form the backbone of peri-operative analgesic techniques and are critical in premedication, sedation, and pain relief.
What is the historical significance of opioids?
Opioids, derived from the poppy plant (Papaver Somniferum), have been used for pain and pleasure for nearly 6 millennia.
How are opioids different from NSAIDs in dosing?
Unlike NSAIDs, opioids can be redosed to achieve the desired level of analgesia.
What are the legal requirements for full µ (mu) opioid agonists (Schedule 2 Controlled Drugs) in the UK?
Full µ agonists must be stored in a locked cabinet, accessed only by a responsible person, and recorded in a Controlled Drugs Register.
What are the legal differences between Schedule 2 and Schedule 3 opioids?
Schedule 3 drugs, like buprenorphine, require safe custody but do not need to be recorded in a Controlled Drugs Register.
Why do some veterinary practices prefer to stock Schedule 3 opioids?
Due to less stringent legal requirements, some practices only stock buprenorphine and butorphanol instead of full µ agonists (Schedule 2).
What limitation does the absence of full µ agonists create in veterinary practices?
The lack of full µ agonists imposes a significant limitation on managing moderate to severe pain in cats.
What are the storage and record-keeping requirements for Schedule 2 Controlled Drugs?
These drugs must be stored in a locked cabinet, and all transactions must be recorded in a Controlled Drugs Register within 24 hours of dispensing.
What are the clinical effects of opioids in cats?
Analgesia, sedation, euphoria, cough suppression, bradycardia, respiratory depression, vomiting, reduced gut motility, and pupil dilation.
How do opioids affect the cardiovascular system?
Opioids can cause bradycardia by stimulating vagal tone, which can be managed by giving anticholinergics like atropine.
What is the effect of opioids on the respiratory system in animals?
Respiratory depression is unlikely with clinical doses in awake animals but can occur with opioids like fentanyl during anesthesia.
Why should morphine be avoided in certain animals?
Morphine can cause vomiting by stimulating the chemoreceptor trigger zone and should be avoided in animals with raised intracranial or intraocular pressure.
How do opioids affect the gastrointestinal system?
Opioids reduce gut motility and stimulate GI sphincters, which can lead to constipation.
What are the effects of opioids on the eyes?
In most species, opioids cause pupil constriction, but in cats, opioids cause pupil dilation.
What risk do opioids pose during pregnancy?
Opioids can cross the placenta and cause respiratory depression in neonates during caesarean sections.
What are the three recognized opioid receptors?
The three opioid receptors are Mu (µ), Kappa (κ), and Delta (δ), which are found in the brain, spinal cord, and peripheral tissues.
Which opioid receptor provides the most potent analgesia in cats?
The Mu (µ) receptor provides the most potent analgesia in cats.
What are the different classifications of opioids based on their receptor activity?
Full agonists (e.g., methadone, fentanyl), partial agonists (e.g., buprenorphine), and antagonists (e.g., naloxone).
What is the difference between opioid potency and efficacy?
Potency refers to the concentration required to elicit a response, while efficacy refers to the maximum effect a drug can achieve.
Why is buprenorphine more potent but less efficacious than morphine or methadone?
Buprenorphine requires a lower concentration to elicit a response (higher potency) but cannot achieve the same maximum analgesia (lower efficacy) as morphine or methadone.
What is the interaction between partial and full Mu receptor agonists?
Buprenorphine (partial agonist) binds tightly to Mu receptors, potentially limiting the efficacy of full Mu agonists like morphine or methadone administered later.
When should buprenorphine not be used for premedication?
Buprenorphine should not be used if administration of full Mu agonists like fentanyl is anticipated during anesthesia.
