After midterm #2 - Ch 11: opiates

Question 1

Intro and overview of opiate family

Answer 1

opiate - drug with properties similar to opimium

Question 2

Source

Answer 2

papaversomniferum - plant makes opium on only 10 days of its life cycle. Seeds scratched so sap leaks out. Opoium is sap scraped off, compressed into cakes

Question 3

Active ingredients

Answer 3

morphine (10%), codeine (<0.5%), thebaine (0.3%)

Question 4

Agonists

Answer 4

narcotic analgesics = “sleepiness” and “relieve pain”

• opiates: opium, morphine, codeine, thebaine
• derivatives: hydromorphone, oxycodone, heroin, etorphine
• synthetic opiates: methadone, meperidine, LAAM, fentanyl

Question 5

Heroin

Answer 5

diacetyl morphine; libid solubility 10x greater than morphine. Gets into brain faster and at a higher concentration

Question 6

Codeine

Answer 6

less potent as analgesic than morphine, produces antitussive (stops coughing) effects at doses that do not cause analgesia; produces less euphoria

Question 7

Oxycodone

Answer 7

from thebaine; sold as Percocet with acetaminophen or percodan with aspirin

Question 8

Meperidine (demerol)

Answer 8

well absorbed orally; often given parenterally; analgesia for severe pain; doesn’t cause pinpoint pupils, dilates pupils

Question 9

Fentanyl

Answer 9

100x more potent than morphine as analgesic; highly lipophilic, rapid onset and short duration of action (15-30 mins); used as epidural during labour and anesthesia and in a transdermal patch

Question 10

Methadone

Answer 10

longer acting, well absorbed orally, maintenance drug for heroin addices

Question 11

desomorphine

Answer 11

synthesized from codeine, street name krokodil due to rough scaly green skin that occurs with repeated use (due to contaminants). Necrosis of limbs, deep abcesses

Question 12

pharmacokinetics administration and absorption - morphine

Answer 12

morphine (base, aka = 8.2), abs poor with oral administration, only about 15-40% available for absorbance; first pass metabolism hy enzymes in digestive system and liver. Given orally because of ease of maintaining blood levels

Question 13

Heroin/morphine administration and absorption

Answer 13

parenterally - iv produces intense and immediate effects.

• vapour of heated heroin inhaled (chasing the dragon)

Question 14

Methadone - administration and absorption

Answer 14

well absorbed orally - 70-80% available, equal to morphine in potency as an analgesic

Question 15

Distribution

Answer 15

• most opiate [] in lungs, liver, spleen, 80-96% bound to blood proteins
• morphine readily crosses placental barrier, but slow to cross BBB (low lipid solubility-
• heroin - highly lipid soluble, readily crosses BBB