Analgesia

Question 1

What are the 5 major classes of analgesic drugs used in veterinary medicine?

Answer 1

(Opioids, NSAIDs, alpha-2 agonists, NMDA-receptor antagonists, and local anesthetics)

Question 2

What are the possible side effects a patient may experience when given an opioid?

Answer 2

(GI upset (big concern, vomiting, ileus), histamine release (particularly when using morphine), sedation, abuse potential, +/- respiratory depression (rare at analgesic dosing))

Question 3

(T/F) Opioids should not be your first choice for chronic pain management.

Answer 3

(T, inevitably will cause inappetence, good for acute, severe pain)

Question 4

In what patients should NSAIDs be avoided?

Answer 4

(Patients that are dehydrated or hypovolemic → aka patients with decreased renal and GI blood flow because can lead to GI ulcers and an inability of the kidneys to adjust to hypotension via auto-regulation by blocking prostaglandins)

Question 5

Why should the use of alpha-2 agonists be avoided in any patients that are not very stable?

Answer 5

(Because alpha-2 agonists induce a significant decrease in cardiac output no matter what dose is given)

Question 6

What are some additional cons to the use of alpha-2 agonists besides significant cardiovascular effects?

Answer 6

(Profound sedation, respiratory depression, and parenteral only)

Question 7

(T/F) You want to negate the cardiovascular side effects of alpha-2 agonists, giving a lower dose will achieve that goal.

Answer 7

(F, there is a 60-70% drop in CO no matter the dose you give so giving a lower dose still gets you decreased CO and a patient that isn’t sedate enough, a classic lose lose)

Question 8

(T/F) NMDA receptor antagonists are most effective if given before the painful stimulus.

Answer 8

(T)

Question 9

What are the cons of using ketamine?

Answer 9

(Behavioral changes (more for premed dosing), best used prior to painful stimuli, muscle rigidity (more for premed dosing), not reversible, +/- inconsistent analgesia)