NBME 23 3,4-Methylenedioxymethamphetamine (MDMA) (NBME Answers)

NBME 23 Answers

nbme23/Block 1/Question#48 (reveal difficulty score)
A 20-year-old man is brought to the emergency ...
3,4-Methylenedioxymethamphetamine (MDMA) 🔍 / 📺 / 🌳 / 📖
tags: psych toxicity

+13 upvote downvote
submitted by ∗azibird(279)

get full access to all content ⋅ pick a username

Who else got this just because it said "all-night dance party?" Applied my knowledge of raves and nothing else.

get full access to all content ⋅ pick a username

chaosawaits that almost ruined me because I remembered all those fun levodopa parties my boys and I used to have. /s +6

imgdoc Idk who takes ketamine at an all night dance party, maybe anesthesiologists? +1

+3 upvote downvote
submitted by ∗mousie(272)

get full access to all content ⋅ pick a username

Why no sweating? I mean I get Ecstasy is probably the drug of choice before an all night dance party (lol) but don't understand why there would be cold extremities and no sweating when is FA it says hyperthermia and rhabdo????

get full access to all content ⋅ pick a username

sympathetikey FA says, "euphoria, disinhibition, hyperactivity, distorted sensory and time perception, bruxism. Lifethreatening effects include hypertension, tachycardia, hyperthermia, hyponatremia, serotonin syndrome." So I think they wanted you to see Sinus Tachy and jump for MDMA. Idk why Ketamine couldn't also potentially be correct though. +13

amorah I picked ketamine because it said no diaphoresis. But if you need to find a reason, I guess the half life of ketamine might rule it out. Remember from sketchy, ketamine is used for anaesthesia induction, so probably won't keep the HR and BP high for 8 hrs. In fact, its action is ~10-15 mins-ish iv. +13

yotsubato Because the NBME is full of fuckers. The guy is probably dehydrated so he cant sweat anymore? +22

fulminant_life you wouldnt see tachycardia with ketamine. It causes cardiovascular depression but honestly i saw " all-night dance party" picked the mdma answer and moved on lol +10

monkd Ketamine acts as a sympathomimetic but oh well. NBME hasn't caught on to ketamine as a drug of recreation :) +6

usmleuser007 Why not LSD? +1

d_holles @usmleuser007 LSD doesn't cause HTN and ↑ HR. +2

sbryant6 @fulminant_life FALSE. KETAMINE CAUSES CARDIOVASCULAR STIMULATION. +12

dashou19 Take a look at why the patient has pale and cold extremities. "Mechanistic clinical studies indicate that the MDMA-induced elevations in body temperature in humans partially depend on the MDMA-induced release of norepinephrine and involve enhanced metabolic heat generation and cutaneous vasoconstriction, resulting in impaired heat dissipation." https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5008716/ +5

drzed @sbryant6 you're both saying the same thing. Ketamine has a direct negative inotropic effect on the heart, but it is also a sympathomimetic. You are both correct. +1

paperbackwriter @drzed Can you please site that? As far as I understand ketamine has a sympathomimetic effect on the CV system --> increased chronotropy and BP. I also don't see how they're saying the same thing. One person said "stimulation" and the other said "depression" +1

nutmeg_liver People tend to drink a lot of water on MDMA. I just guessed the confusion was a result of hyponatremia (too much free water) but no idea if there's any data saying that people tend to become hyponatremic due to water over-consumption on MDMA lol. +2

cassdawg "Despite possessing a direct negative cardiac inotropic effect, ketamine causes dose dependent direct stimulation of the CNS that leads to increased sympathetic nervous system outflow. Consequently, ketamine produces cardiovascular effects that resemble sympathetic nervous system stimulation. Ketamine is associated with increases in systemic and pulmonary blood pressures, heart rate, cardiac output, cardiac work, and myocardial oxygen requirements."(https://www.openanesthesia.org/systemic_effects_of_ketamine/) +1

brise LSD does cause HTN and tachycardia according to uworld! @d_holles +2

+3 upvote downvote
submitted by macrohphage95(10)

get full access to all content ⋅ pick a username

MDMA is the only hallucinogen that has sympathetic activity as it is derived from methamphethamines ( look at its name) ... that explains everything.

get full access to all content ⋅ pick a username

tyrionwill Yes, good point to remember. In the category of FA stimulants, 2 agents has sympathetic activity: 1)MDMA; 2)PCP +

jackie_chan Basically how I solved it, all the other drugs are downers +

jackie_chan Even tho ketamine has sympathomemetic effects, they would be widly tripping, they dont call it falling into a K-hole for nothing. +

+2 upvote downvote
submitted by ∗bmilt34(1)

get full access to all content ⋅ pick a username

Ok I think this is a bad combination of 1) a poorly written question, 2) a potenital miss-understanding by the writer and, 3) a expectation for the recall of esoteric information complicated by the 8 hours which have elapsed since the ingestion

Here's what I think: 1) they done goofed by saying there is no diaphoresis. We have all seen what MDMA does to people's eccrine glands - moreover people drink ...a lot (thus causing the classic low Na which causes seizures) 2) It's weird that he would have tachycardia but none of the other sx of MDMA intoxication 3) I guess we are suppose to know and/ or reason that even though MDMA causes hyperthermia, it also has sympathetic effects (increased release/inhibited repute of adrenaline, norepinephrine, serotonin, and dopamine) which could cause the cold extremities

get full access to all content ⋅ pick a username

+2 upvote downvote
submitted by medstudent22(12)

get full access to all content ⋅ pick a username

Sweating is mediated by the sympathetic nervous system, but is through Acetylcholine (Remember - Anti-Muscarinic poisoning = Dry as a bone because no sweating). It all points to NE overdose (mimicked by an amphetamine) --> Tachycardia (NE @ beta-1), Hypertensive (NE @ alpha-1), Pale + Cold = vasoconstriction (NE @ alpha-1)

Key point - sweating will not be stimulated by NMDA.

Not exactly sure why ketamine is NOT the answer (maybe it doesn't lead to peripheral vasoconstrictive properties)? But NMDA does fit the picture!

get full access to all content ⋅ pick a username

+0 upvote downvote
submitted by ∗brise(86)

get full access to all content ⋅ pick a username

How do you rule out LSD? It also causes tachycardia!

get full access to all content ⋅ pick a username

Must-See Comments from nbme23

ferrero on Precapillary resistance
yotsubato on 99%
sne on Triglyceride
sajaqua1 on Area labeled ‘D’ (Spinothalamic tract, right)
stinkysulfaeggs on Hypoglycemia
hayayah on Iris
soph on Peak inspiratory pressure (alveolar): ...
seagull on Area labeled ‘C’ (Cranial nerve 8: ...
water on Dietary change
wired-in on 28.8
beeip on Binding of permeable ligand to nuclear ...
thomasalterman on Hypoglycemia
yotsubato on Inhibition of the cytochrome P450-dependent ...
seagull on Decreased sodium bicarbonate reabsorption in ...