Substance Use

Question 1

Alcohol is a tiny molecule! What does this imply about it’s absorption rate? What are the main determinants of absorption rate via the stomach?

Answer 1

• small molecule = crosses membranes easily by diffusion

- rate of absorption is mostly determined by contents of stomach and concentration of alcohol (ex. whiskey vs. beer)

Question 2

What are some therapeutic uses for alcohol?

Answer 2

• skin disinfectant
• nerve block
• solvent/preservative for some oral and topical preps
• appetite stimulant
• treatment of methanol and ethylene glycol poisoning

Question 3

What two enzymes are important for alcohol metabolism and where are they located?

Answer 3

1) alcohol dehydrogenase (ADH) - liver cytoplasm

2) acetaldehyde dehydrogenase (ALDH) - liver mitochondria

Question 4

What metabolizing system is induced by high levels of alcohol or chronic use?

Answer 4

Microsomal Ethanol Oxidizing System (P450-CYP2E1)

Question 5

A patient comes to you hoping to decrease their alcohol use. They’ve been trying to gradually cut back, but then they find themselves drinking pitchers at noon all over again. What is one drug you can suggest and how does it work?

Answer 5

Disulfiram - this inhibits acetaldehyde dehydrogenase, allowing acetaldehyde to build up after indulging in alcohol; induces nausea/vomiting/headache

Question 6

You’re covering in the ER and a group of college students bring their friend in. She is in a stupor like state and is very non-responsive to stimuli. They say she was fine at the bar and was chatting it up with some guy, then went to the bathroom, returned, and was like this about half an hour later. What drug and drug class do you suspect she was exposed to (besides alcohol)?

Answer 6

Flunitrazepam (“roofie”), a benzodiazepine

Question 7

You’re watching the movie “Blow” with friends and they decide to see if med school is actually teaching you anything important. They ask you how cocaine works; what’s your answer?

Answer 7

blocks the reuptake transporter for DA, NE, and 5HT, allowing those NTs to have longer excitatory effects on postsynaptic receptors. Suck it, friends!

Question 8

You’re in the ER and a mom frantically runs in with her toddler because he was playing outside and got into some antifreeze. What do you administer to reduce the harmful metabolites and how does this work?

Answer 8

fomepizole, which blocks alcohol dehydrogenase

Question 9

What is the stimulatory effect of nicotine on the CNS?

Answer 9

activates nAChRs on VTA dopamine neurons which results in DA release in nucleus accumbens and prefrontal cortex

Question 10

What is the action in your brain of your daily cup of morning joe (or however you take your caffeine)?

Answer 10

• antagonist at inhibitory adenosine receptors

Question 11

You’re on surgery rotation and a patient comes in for an emergency appendectomy. He admits to you that he’s nervous, because it’s been awhile since he’s gone a day without heroin. What do you administer throughout his hospital stay to make sure he doesn’t start having withdrawal symptoms?

Answer 11

methadone

Question 12

You’re doing a shift in the ER and a patient is brought in strung out on oxycodone. What are the opiate receptor antagonists?

Answer 12

naloxone (usually used), nalmefene, naltrexone

Question 13

How do hallucinogens like LSD work?

Answer 13

agonist of 5HT2A receptors on raphe cell body, which inhibits raphe nuclei firing. This results in a disinhibition of sensory input.

Question 14

MDMA and mescaline are examples of what class of hallucinogens?

Answer 14

phenylethylamine derivatives

Question 15

LSD and psilocybin are examples of what class of hallucinogens?

Answer 15

indole alkyl amine derivatives

Question 16

What are some potential negative effects of hallucinogens?

Answer 16

• bad trips (panic attack)
• flashbacks (trigger emotional past experience without taking drug)
• chronic psychoses
• chromosome damage and teratogenicity

Question 17

What are the endogenous ligands of cannabinoid receptors? What is their effect?

Answer 17

Arachidonic acid derivatives, such as anandamide.
- key role in regulation of energy balance, lipid and glucose metabolism (food intake, CB2), and participation in brain reward system (CB1)

Question 18

At oncology clinic, you follow up with a patient that is doing well at home but has had a lot of trouble with appetite, nausea, and vomiting recently. What is a drug that you can suggest be used and how does it work?

Answer 18

dronabinol (schedule III), a synthetic THC that stimulates cannabinoid receptors

Question 19

You’re on an inpatient floor, and one of your patients is in late stage of AIDS. He’s having trouble with nausea and vomiting, and has almost no appetite. He jokes that when this happens at home, he usually just smokes a joint. Brilliant! What do you give him?

Answer 19

Nabilone (schedule II), a synthetic THC

Question 20

A patient comes to the ER after having believed he was invincible and running across rooftops even after he fell once and broke his legs. He’s hostile and mean, and you suspect he has been using PCP. How does this drug work?

Answer 20

antagonist of ion channel on NDMA receptor and an agonist at opioid receptors