Substance Use Flashcards
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?
- 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)
What are some therapeutic uses for alcohol?
- skin disinfectant
- nerve block
- solvent/preservative for some oral and topical preps
- appetite stimulant
- treatment of methanol and ethylene glycol poisoning
What two enzymes are important for alcohol metabolism and where are they located?
1) alcohol dehydrogenase (ADH) - liver cytoplasm
2) acetaldehyde dehydrogenase (ALDH) - liver mitochondria
What metabolizing system is induced by high levels of alcohol or chronic use?
Microsomal Ethanol Oxidizing System (P450-CYP2E1)
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?
Disulfiram - this inhibits acetaldehyde dehydrogenase, allowing acetaldehyde to build up after indulging in alcohol; induces nausea/vomiting/headache
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)?
Flunitrazepam (“roofie”), a benzodiazepine
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?
blocks the reuptake transporter for DA, NE, and 5HT, allowing those NTs to have longer excitatory effects on postsynaptic receptors. Suck it, friends!
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?
fomepizole, which blocks alcohol dehydrogenase
What is the stimulatory effect of nicotine on the CNS?
activates nAChRs on VTA dopamine neurons which results in DA release in nucleus accumbens and prefrontal cortex
What is the action in your brain of your daily cup of morning joe (or however you take your caffeine)?
- antagonist at inhibitory adenosine receptors
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?
methadone
You’re doing a shift in the ER and a patient is brought in strung out on oxycodone. What are the opiate receptor antagonists?
naloxone (usually used), nalmefene, naltrexone
How do hallucinogens like LSD work?
agonist of 5HT2A receptors on raphe cell body, which inhibits raphe nuclei firing. This results in a disinhibition of sensory input.
MDMA and mescaline are examples of what class of hallucinogens?
phenylethylamine derivatives
LSD and psilocybin are examples of what class of hallucinogens?
indole alkyl amine derivatives
What are some potential negative effects of hallucinogens?
- bad trips (panic attack)
- flashbacks (trigger emotional past experience without taking drug)
- chronic psychoses
- chromosome damage and teratogenicity
What are the endogenous ligands of cannabinoid receptors? What is their effect?
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)
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?
dronabinol (schedule III), a synthetic THC that stimulates cannabinoid receptors
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?
Nabilone (schedule II), a synthetic THC
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?
antagonist of ion channel on NDMA receptor and an agonist at opioid receptors
