Antibacterials (ABX) Practice Exam 2026 - Free Antibacterial Practice Questions and Study Guide

The key idea is that some antibiotics can affect serotonin levels by inhibiting monoamine oxidase. Linezolid has MAO-inhibiting (MAOI-like) properties, which means it can raise serotonin when someone is already taking an SSRI. Using this antibiotic with SSRIs can trigger serotonin syndrome, a dangerous condition with symptoms like agitation, high body temperature, autonomic instability, and neuromuscular changes. Because of this MAOI-like effect, linezolid is avoided or used with extreme caution alongside SSRIs, often with monitoring or a washout period.

The other antibiotics shown do not inhibit MAO, so they don’t carry this specific interaction risk with SSRIs, though they have their own potential interactions and side effects.