Dr. Christopher Carrubba and Dr. Brian Radvansky, and Dr. Taylor Purvis contributed to this article.
Let’s face it—some things just have to be memorized. While the USMLE is full of conceptual material that apt students can reason their way through, it is also comprised of material requiring brute force memorization for mastery.
Fortunately, mnemonics can be an anxious, overworked medical student’s best friend. And, better yet, they can help you grab a lot of points on your USMLE. Utilize these tricks and watch your scores climb higher than before.
One topic that does better with mnemonic memorization than it does with pure reasoning is the antiarrhythmics. There are umpteen drugs spread across 4 categories, all with names that do us no favors. Use these mnemonics to help keep everything in its right place.
Topic: Keeping Class I-IV Antiarrhythmics Straight
Mnemonic: Some Block Potassium Channels
Do you ever have a hard time remember which class of antiarrhythmic targets sodium and which targets potassium? You can keep the overall organization of the antiarrhythmics straight with the mnemonic Some Block Potassium Channels.
Some Block Potassium Channels
Some = Sodium channel blockers (class I)
Block = Beta Blockers (class II)
Potassium = Potassium channel blockers (class III)
Channels = Calcium channel blockers (class IV)
Topic: Class I Antiarrhythmics
Mnemonic: Double Quarter Pounder, Lettuce Mayo, Fries Please
Pharmacology is one of those subjects that you just have to memorize. Mechanisms of action, side effects, and common uses of medications are high-yield material for the USMLE that cannot be answered any other way.
While there are hundreds of drugs that are fair game on the exam, learning their properties can often be made easier by lumping drugs into medication classes. Sometimes, this can be very easy. Whoever decided to name all of the statins, “______statin,” clearly had medical students in mind. Other times, we are not that fortunate. Alas, the bane of antiarrhythmics.
If you are scared of these drugs, you’re not alone—many medical students have found themselves panicking as none of the antiarrhythmics sound alike, there are four separate classes, and each has a seemingly complicated mechanism of action. Fortunately, the following tricks work wonders.
Our general recommendation for anxiety-inducing topics like this is to hammer them hard enough that mastery replaces anxiety. You want to put in enough time and effort so that instead of seeing a question and saying, “Crap, an antiarrhythmic question,” you say “All right! Antiarrhythmics!” It sounds silly, but will help boost confidence and put you in a better mindset for test day.
💡 Class I Antiarrhythmics are the sodium channel blockers, and these are further classified as Class IA, IB, and IC.
To remember these, try Double Quarter Pounder, Lettuce Mayo, Fries Please:
- Class IA = Disopyramide, Quinidine, and Procainamide
- Class IB = Lidocaine and Mexiletine
- Class IC = Flecainide and Propafenone
Eesh, 7 drugs, and we are only in class one. Let us see if we can smooth things out a bit. Memorizing which classes have positive and negative effects on the effective refractory period/action potential duration and level of sodium channel blockade is certainly not high-yield. They are all factoids which likely won’t help you on the test outside of a singular question, and unless you find yourself in an electrophysiology fellowship, probably won’t be too much use either.
Also, now that Step 1 is pass/fail, the Step 2 ethos of clinical application becomes all the more valuable. Ergo, let us approach this from an indication standpoint.
It’s likely the anesthesiologist in me talking, but your most important drug here is lidocaine. It has indications as a local anesthetic, an analgesic, and as a rhythm stabilizer. It can be deployed for VENTRICULAR arrhythmias like ventricular tachycardia and ventricular fibrillation.
Probably the next most important on this list is procainamide, which is used for Wolff-Parkinson-White syndrome (the pre-excitation syndrome with delta-waves, a USMLE read-this-EKG favorite), and ventricular arrhythmias that don’t respond to other treatments.
Flecainide is becoming more popular, and has usage for atrial fibrillation and other supraventricular arrhythmias. The other drugs here are relatively low yield. Remember their category, but don’t overstudy the finer points of all of them.
Topic: Class II Antiarrhythmics
Mnemonics: MANBABE, Not Your Usual -olol, PArtial Agonists, ABCD
💡 Class II Antiarrhythmics are the beta blockers. Remember, these all end in ___lol (metoprolol, propranolol, carvedilol, etc.)
Thank goodness there’s some logic in this naming system! Beta-blockers are so common in clinical practice; you will definitely come across them with great frequency. They are indicated during myocardial infarctions to reduce myocardial oxygen demand (as long as your patient is not hypotensive). Heart failure patients also benefit from their administration. They can be used for supraventricular tachycardias (tachycardias that originate above/before the ventricles). These include paroxysmal SVT, atrial fibrillation with rapid ventricular response, and sinus tachycardia.
For this class, we have FOUR mnemonics for you to use!
Mnemonic #1: MANBABE
You might want to keep track of the cardioselective beta blockers that act primarily on the cardiac B1 receptors. Remember the mnemonic “MANBABE.”
MANBABE
Metoprolol
Acebutolol
Nebivolol
Betaxolol
Atenolol
Bisoprolol
Esmolol
Mnemonic #2: Not Your Usual -olol
To remember which beta blockers have BOTH beta and alpha blocking ability, think of the ones that don’t have the typical “-olol” ending. These are:
Not Your Usual -olol
Carvedilol (-ilol)
Labetalol (-alol)
Mnemonic #3: PArtial
To remember the partial agonists, remember they are just PArtial:
PArtial
Pindolol (NOT propranolol)
Acebutalol (NOT atenolol)
Mnemonic #4: ABCD
While we’re here, let’s touch upon beta-blocker side effects and contraindications. Side effects include [orthostatic] hypotension, fatigue, heart block, sexual dysfunction, and possible bronchospasm.
For the contraindications, remember the mnemonic ABCD:
ABCD
A = Asthma (beta-2 agonism can narrow airways
B = Block (heart block should not be further blocked!)
C = (C)HF – Tricky one. While utilized in the chronic management of heart failure, patients with acute decreases in contractility should not be beta-blocked.
D = Diabetes – More theoretical. Beta-blockade can shadow a hypoglycemic event.
Topic: Class III Antiarrhythmics
Mnemonic: AIDS
💡 Class III Antiarrhythmics are the potassium channel blockers, which can be memorized with the mnemonic AIDS.
AIDS
A = amiodarone
I = ibutilide
D = dofetilide
S = Sotalol
Of these, your golden child is amiodarone. It is used for refractory VT and VF (think ACLS algorithm), and can be an acute and chronic solution to atrial fibrillation.
It’s useful to remember that side effects of amiodarone can affect your “_____ function tests.” Liver, thyroid, and pulmonary.
Topic: Class IV Antiarrhythmics
Mnemonic: DDDD
💡 Class IV Antiarrhythmics are the calcium channel blockers verapamil and diltiazem.
When it comes to calcium channel blockers, one of my favorites was memorizing them in two classes. You have your centrally acting ones that focus on heart rhythm (non-dihydropyridines), as above. Members of the other class (dihydropyridines) all end in -dipine (e.g., nicardipine, amlodipine).
DDDD
Dipines act Distally through vasoDilation and can cause eDema.
Now all the book reading and tables and charts in the world won’t help you internalize memories nearly as well as patient experiences. If you were at the code in the ED and can remember the team running the code asking for lidocaine and amiodarone, you have “experience” with these medications instead of just reading about them. If you remember your patient has an amlodipine “allergy” (e.g., “It made my legs swell up!”), this side effect will forever be with you. Book learning is a necessity, but is no substitute for clinical experience. Get out there and get some!
