What Dr. Wood Told You to Star

QT prolongation said twice

“Anytime we see QT prolongation, you should star that, underline it, whatever you need to do.”

… and again: “… that causes QT prolongation — star it, underline it, it’s good to know.”

It spans three classes on this exam: macrolides (worse with class Ia and III antiarrhythmics and with electrolyte abnormalities), fluoroquinolones, and posaconazole (whose QT risk runs mostly through the hypokalemia and hypomagnesemia it causes). He flagged it the first time it appeared and again three minutes later.

What he actually taught around it: the QT interval is how long the ventricle takes to repolarize, and it lengthens because the drug blocks the potassium channel that lets K⁺ out of the cell — the slide names it the hERG channel. A long enough QT degenerates into torsades de pointes, French for “twisting of the points”, a ventricular arrhythmia he called not compatible with life. Three things multiply the risk: a congenital long QT, several QT-prolonging drugs stacked together, and electrolyte disturbance — a single Z-Pak in a healthy person did not worry him. The treatment of choice for torsades is magnesium sulfate, two grams, which he called the “two gram slam” and said was worth remembering.

MRSA coverage said once, emphatically

“Again, anytime you see MRSA coverage — star it, highlight it, underline it, right? Pseudomonas, C. diff, those are all things you want to be thinking about. Kind of big notable bugs.”

On this exam the agents with MRSA coverage are vancomycin, linezolid, clindamycin, ceftaroline, tetracyclines and tigecycline (not VRE), plus topical mupirocin. He introduced Staphylococcus aureus early as “a very notable bug… especially when we talk about the dreaded MRSA.”

Teratogenic drugs said once, about itraconazole

“This is also an example of a drug that is teratogenic. That means it can cause harm to a fetus, and so you would need to check a pregnancy prior to giving this. So anytime we see a teratogenic drug, also note that, because it can be very significant — especially because a lot of patients, when they’re first pregnant, may not know it, and they can go weeks before they know.”

The teratogens on this exam are itraconazole, fluconazole and voriconazole (the last two “teratogenic in animals”), plus isotretinoin, which he called extremely teratogenic in Lecture 2 and placed in pregnancy category X — his definition: “no situation in which the benefits of this drug outweigh the risk to a developing fetus,” with effects running from malformation to fetal death. Topical retinoids are avoided in pregnancy as well, and tetracyclines in the second and third trimesters — stated as an outright contraindication when he restated it in Lecture 2. The action he wants is the same every time: check a pregnancy test before you prescribe to anyone of childbearing potential.

Rebound after three days said and he said students always miss it

“For whatever reason, even though I highlight it every time I talk about this drug, I always talk about which of these drugs can cause rebound nasal stuffiness, or rebound ocular redness, when used for more than three days. And for whatever reason, students have a really tough time with this one… if you get it wrong on the test, which I hope you don’t, you’ll be able to say, oh, he did warn me about that. I should have underlined it, starred it, whatever.”

This is oxymetazoline (Afrin) and the condition is rhinitis medicamentosa — rebound congestion from overstimulated alpha receptors downregulating, so the congestion returns when the drug stops. He notes it needs a taper, not an abrupt stop. Worth noting: he flagged this harder than any other single fact in Lecture 3.

Pneumonia + hotel + contaminated air conditioning → Legionella

“If you ever see a test question — ever, ever, ever, on the PANCE or anywhere else — where it says, hey, the patient was coming in for a pneumonia and they were at a hotel and the AC unit was contaminated, it’s always Legionella.”

He then gave the reason it is a stock stem: Legionnaires’ disease was discovered from Legionella contaminating an air-conditioning unit during an American Legion convention at a hotel. He called it a classic scenario. Legionella is an atypical, so the answer is a macrolide, a tetracycline or a respiratory fluoroquinolone.

Red head to toe + itching + infused over 30 minutes → vancomycin

“If I said, okay, test question — a patient was getting an antibiotic infused and all of a sudden they’re red from head to toe and complaining of some itching, medication was infused over 30 minutes. What’s most likely to cause that?”

He answered it himself: vancomycin infusion syndrome — and gave the fix, which is running it over about two hours rather than 30 minutes. The infusion RATE is the whole answer; this is not an allergy.

Toxic shock after a retained tampon → clindamycin

“This can also be used for things like toxin-mediated diseases, because the clindamycin can actually bind to the toxin. So if you ever hear of toxic shock syndrome — or the classic sort of presentation is, a girl left in a tampon for too long and then all of a sudden gets septic shock from that, due to toxins being released by bacteria — clindamycin can be utilized for that.”

He calls it “a unique sort of point” for clindamycin. The mechanism is the thing to carry: it binds the toxin, which is why it beats an agent that merely kills the organism in a toxin-mediated illness.

Acne, benzoyl peroxide too irritating → topical retinoid

“If I say on a test question — hey, they’re presenting for treatment for acne, they say they use benzoyl peroxide but it’s just that their skin got so irritated they didn’t want to continue it. What do you go to next? Topical retinoids kind of makes sense from that standpoint.”

A next-step stem rather than a diagnosis one. He set it up by saying that if the patient has not tried anything yet, starting with benzoyl peroxide is perfectly reasonable — so the stem turns on what they already failed and why.

Time spent is the signal

“If I spend a lot of time talking about something, I’m probably thinking about that when writing test questions. So you can use that sometimes to get clues on what maybe I’m thinking about for specific questions.”

Learn the band, not the member

“Focus on categorizing these meds into as big of a band as you can for each group. Don’t memorize each individual side effect for every individual penicillin. Just know that all penicillins have the same side effects, they all have the same mechanism. The differences between them would be things like, which one has anti-pseudomonal coverage? Which ones are specifically for MSSA?”

The beta blocker letter rule

“For the beta blockers, generally speaking, if the beta blocker starts with the letter N through Z, it is considered a non-selective beta blocker… A through M as in Mary are generally going to be considered the cardioselective beta blockers.”

What he said he will NOT do

“Am I going to be so mean on the test that I would have you differentiate nebivolol? No, that’s kind of an exception to the rule. I’d rather you get the rule down first and then we can focus on the exceptions… I’m not going to try to be sneaky with you.”

But he did name the two exceptions he would focus on: labetalol and carvedilol, because they carry additional alpha-1 blockade and are also non-selective.