Opioid Analgesics & Antagonists

Question 1

Morphine (prototype)

Answer 1

glucoroniadation (3 inactive, 6 active) kidney excrete
Block incoming pain signals, alter pain perception, activate descending inhibitory pathways
Mu Opioid receptor
half life = 5 hrs, give 6x dose PO

Question 2

Codeine

Answer 2

Antitussive

Act centrally, little Mu activity, avoid in patients on MAOI (fatal interaction)

Question 3

Diphenoxylate & Loperamide

Answer 3

Antidiarrheal, oral
Increase GI tone, decrease peristalsis & emptying
Constipation issue and Diphen. not H2O soluble

Question 4

Opioid Problems

Answer 4

Dependence, tolerance, Respiratory depression, N/V, sedation, constipation, thermoregulation, overdose

Question 5

Meperidine

Answer 5

half life of 3 hours
OB ward- decrease resp. depression in newborn and less prolonging of labor
Normeperidine = toxic (from liver metabolism)
No miosis & MAOI interaction

Question 6

Methadone

Answer 6

oral, half life = 12-40 hours
Mu agonist and NDMA partial agonists
chronic pain & detox

Question 7

Fentanyl

Answer 7

80-100x more potent than morphine
general and epidural anesthesia
lollipops and patches

Question 8

Oxycodone

Answer 8

PO with good bioavailabilty

street drug and fatal overdose

Question 9

Tramadol

Answer 9

Mu agonist; block 5-HT and NE reuptake

decrease seizure threshold

Question 10

Buprenorphine

Answer 10

(mixed agonist) Partial Mu agonist: ceiling effect
Antagonize other agonist; hard to antagonize
25-50x more potent than morphine; lollipops
help get abusers off of heroine

Question 11

Nalaxone

Answer 11

Antagonist
Bind receptor and doesn’t activate
No effect in normal people but leads to sever withdrawal in abusers (titrate)
half life = 1-2 hrs

Question 12

Nalrextone

Answer 12

Antagonist

Longer half life and block opioid effect (compliant abusers)