(08) Narcotic Analgesics

Question 1

1. What is a useful and inexpensive analgesic and sedative, used widely along in dogs?
2. selective or no?
3. can it be used orally?

why?

Answer 1

1. morphine
2. non-selective opiod agonist
3. no

highly metabolized during its first pass through liver and trapped in the stomach of animals who have highly acidic gastric fluids

Question 2

1. What is a potent analgesic agent by its interaction with kappa receptors?
2. How relative to morphine (potency, deficiency)?
3. more or less respiratoy/gi depressant effects than morphine?
4. What else can it do?

Answer 2

1. Butorphanol
2. It is a long acting narcotic analgesic that is 4-7 times more potent than morphine but less efficacious.
3. Used clinically, it produces fewer respiratory depressant and GI effects than morphine
4. Butorphanol may be useful to reverse a morphine-induced respiratory depression but still provide some analgesia

Question 3

1. What 3. Nalorphine is a partial narcotic analgesic agonist that is inexpensive an a sufficiently weak agonist that it is used to reverse opioid activity?
2. Unfortunately it also has enough agonistic activity that it can induce what at high doses?
3. The respiratory depressant effect of nalorphine can be antagonized by what?

Answer 3

1. nalorphine
2. respiratory depression (so readministration should be done with caution)
3. naloxone

Question 4

1. What is a pure optiod antagonist?
2. . It is relatively non-selective and expensive - does it have respiratory depressant effect?
3. . It is short acting, so how much you administer?

Answer 4

1. naloxone
2. no
3. so it must be readministered frequently until the opioid agonist has worn off.

Question 5

1. What is an opiate that is about 10 times more potent than morphine,?
2. more or less

respiratory depression

sedation

Answer 5

1. oxymorphone
2. less

more

Question 6

1. What is a potent (about 100-150 times) more potent than morphine—and short acting opioid agonist
2. usually mixed with what as a neuroleptoanalgesic mixture?
3. It is usually coadministred with what?

Answer 6

1. Fentanyl
2. major tranquillizers
3. droperidol

Question 7

1. Can The antitussive effect of an opiod agonist be reversed by an opioid antagonist?

Answer 7

1. no

Question 8

1. Do opiate antagonists and partial agonists stimulate receptors maximally?
2. Compared to either butorphanol or fentanyl, diprenorphine has the more or least analgesic efficiacy.

Answer 8

1. no
2. least

Question 9

1. 9. Opiates reduce neuronal transmission by doing what?
2. Opiate analgesic drugs alleviate pain by doing what?

Answer 9

1. opening neuronal K channels
2. decreasing neurotransmitter release from pain transmitting neurons in spinal cord and brain.

Question 10

1. 10. Morphine decreases propulsive movements of what?

Answer 10

1. intestine and clamp sphincters

Question 11

1. 11. Morphine is a useful analgesic in horses if its administration is preceded by a large dose of what?

Answer 11

1. an appropriate sedative, such as xylazine

Question 12

1. What is a weak narctoic analgesic (1/3 morphine’s potency) use for equine colic?
2. agonist of what?
3. can also decrease the analgesic actions of what?
4. It may even precipitate withdrawal in highly dependant individuals
5. Its sigma activity results in what?

Answer 12

1. pentazocrine
2. kappa
3. of B-endorphin that are mediated by mu-opioid receptors
4. dysphoria