Sketchy Pharm: Opiates, Naloxone, Naltrexone

Question 1

What are the three kinds of opioid receptors?

Answer 1

Mu, kappa, and delta

Question 2

Most of the effects of opioids are mediated by the _________ receptors.

Answer 2

Mu (Mu-ssage)

Question 3

What type of receptor is the mu opioid receptor –and what is the effect of agonizing it?

Answer 3

It is a G-protein that leads to the closure of calcium channels and opening of potassium channels – particularly on neurons – which leads to the hyperpolarization of the membrane and lessened likelihood of action potential transmission. (Think of the open banana barrels and the closed Cali-Yum cooler.)

Question 4

Which neurons are most susceptible to opioid stimulation?

Answer 4

Presynaptic neurons (the guy unplugging the presynaptic extension cord)

Question 5

_________ is a weak mu-opioid agonist.

Answer 5

Tramadol (the tramadol train in the background – the background representing weakness)

Question 6

Fentanyl and morphine stimulate ___________.

Answer 6

the mu-receptor (MORe fuN; make your pain a FaNTAsy)

Question 7

Why is tramadol such a great drug for neuropathic pain?

Answer 7

Because it is not only a weak mu-opioid agonist, it also inhibits the reuptake of norepinephrine and serotonin!

Question 8

Which parts of the GI tract have mu-opioid receptors?

Answer 8

Stomach, small intestine, and large intestine

Question 9

What physical property makes loperamide an interesting and useful opioid?

Answer 9

Loperamide (lop-eared rabbits) cannot pass through the BBB and so has no analgesic effects. It can, however, be used as a great anti-diarrheal.

Question 10

What is another drug with similar properties to loperamide?

Answer 10

Diphenoxylate (the dolphin fountain)

Question 11

Codeine is an _____________.

Answer 11

opioid antitussive

Question 12

What drug, like codeine, is an opioid that suppresses cough?

Answer 12

Dextromethorphan (the dextromethorphan orphan – mascot of the cough drops)

Question 13

There is another mnemonic on the cough-drop bag with the dextromethorphan orphan. What is it?

Answer 13

The camel! It represents NMDA (because camels are nomadic) and it is tethered to a post – symbolizing how dextromethorphan antagonizes NMDA receptors.

Question 14

What are the side effects of opioids?

Answer 14

CNS depression, causing respiratory depression

Miosis (hoodie)

Constipation

Question 15

Most of the effects of opiates develop tolerance, but two do not. What are they?

Answer 15

Miosis and constipation (these are big, remember!); this is represented by the janitor showing that not all are tolerated

Question 16

What is the phenomenon of opioid hyperalgesia?

Answer 16

The reason it occurs is not known, but some patients develop hyperalgesia with chronic opioid use.

Question 17

What are the symptoms of opioid withdrawal?

Answer 17

Lacrimation
Salivation
Diarrhea
Mydriasis
Anxiety
Hyperventilation
Hyperthermia

All things opposite of what opiates do.

Question 18

Methadone is a potent opioid agonist. Why not just give them morphine or heroin?

Answer 18

Methadone has a loooooong half-life and thus the withdrawal effects of methadone are not as acute (think of the long tapering flag above the DONE timer where the guy is getting out of the withdrawal pool).

Question 19

What is a partial agonist that is used to treat opiate withdrawal?

Answer 19

Buprenorphine (the buprenorphine blueprint)

Question 20

The partial mu-opioid agonists have what commonality in their names?

Answer 20

Bu-phine: buprenorphine, nalbuphine, and butorphanol

Think of the Blue Fin grill with the partial massage (the foot massage)

Question 21

The two mu-opioid antagonists are ____________.

Answer 21

naloxone (no lax zone –don’t relax) and naltrexone (no tricks zone)