Analgesics

Question 1

bind to opioid receptors in brain and spinal cord in regions involved in pain modulation and transmission
-achieve euphoria, respiratory depression and physical dependence (mu)

Answer 1

opioids

3 receptors: mu, kappa, and delta
G protein-coupled receptors that decrease cellular excitability

Question 2

Spinal opioid analgesia

Answer 2

• inhibition of the presynaptic Ca2+ channel in the dorsal horn, reducing NT release
• open K+ channels in the postsynaptic neuron afferent causing hyperpolarization
  note: all 3 opioid receptors are heavily localized in the dorsal horn of the spinal cord

Question 3

symptoms of opioid dependence and withdrawal

Answer 3

rhinorrhea, lacrimation, yawning, chills, gooseflesh, hyperventilation, hyperthermia, mydriasis, muscle aches, vomiting, diarrhea, anxiety, hostility

Question 4

higher level pain modulation by opioids

Answer 4

inhibit pain signal transmission from the spinal cord

Question 5

strong mu receptor agonists

Answer 5

morphine
heroin
methadone
fentanyl
meperidine
hydromorphone (dilaudid)
oxymorphone

Question 6

partial agonist or mu receptor

-demethylated to morphine which has higher mu affinity

Answer 6

codeine

Question 7

low analgesic activity but has additive effect

Answer 7

propoxyphene

Question 8

moderate analgesic efficacy

Answer 8

hydrocodone + acetaminophen = lortab

oxycodone + acetaminophen = percodan

Question 9

strong kappa opioid agonist & mu receptor agonist

Answer 9

nalbuphine

Question 10

partial mu receptor agonist used for opioid addiction

Answer 10

buprenorphine

Question 11

kappa agonist/ mu partial agonist or antagonist

*note kappa activation is associated with depression

Answer 11

butorphanol (Stadol)

Question 12

kappa agonist/weak mu antagonist

*note kappa activation is associated with depression

Answer 12

pentazocine (Talwin)

Question 13

weak mu agonist
antimuscarinic
5-HT reuptake blocker
Caution: with SSRI & MAOI
note: lowers seizure threshold

Answer 13

Tramadol (Ultram)

Question 14

Special considerations with opioids

Answer 14

• don’t give with MAOIs as causes hyperpyrexic coma
• antipsychotics increase sedation and cardiovascular effects
• sedative-hypnotics increase CNS depression
• metabolites can cause convulsions

Question 15

found in the dorsal horn after tissue injury & inflammation and is proposed to increase pain & induce a long-lasting hyperalgesia
independent of the opioid receptor system

Answer 15

dynorphins

Question 16

side effect of fentanyl & sufentanil

Answer 16

truncal rigidity
(interferes with ventilation)

Question 17

meperidine causes less resp depression

Answer 17

good for use in labor

Question 18

enhance analgesic actions of opioids

Answer 18

amphetamines