American Board of Medicolegal Death Investigators (ABMDI) Practice Exam

Which types of drugs can cause arrhythmias?

1. Opioids, cyanide, and antacids

2. Tricyclic antidepressants, cardiac drugs, cocaine, dilantin

3. SSRIs, acetaminophen, and amoxicillin

4. Anesthetics, beta-blockers, and diuretics

The correct answer is: Tricyclic antidepressants, cardiac drugs, cocaine, dilantin

Arrhythmias, which are irregular heartbeats, can be caused by various substances, especially certain types of drugs that influence the heart's electrical conduction system. The correct answer highlights a group of drugs well-known for their potential to induce arrhythmias. Tricyclic antidepressants are particularly notorious as they can block sodium channels, leading to a risk of conduction delays and various forms of arrhythmia. Cardiac drugs, such as digoxin or antiarrhythmics, are designed to manage heart rhythm but can also paradoxically affect it if used improperly or at inappropriate doses. Cocaine is a stimulant that can increase heart rate and cause abnormal heart rhythms due to its effects on the central nervous system and its influence on norepinephrine release, which stimulates the heart. Dilantin, or phenytoin, although primarily an anticonvulsant, can also have cardiovascular effects and may lead to arrhythmias, especially in cases of toxicity or rapid infusion. The other drug types listed do not have a strong association with inducing arrhythmias. Although opioids can affect heart rate and potentially lead to bradycardia, they are not typically known for causing significant arrhythmias. Similarly, the combination of SSRIs, acetaminophen, and