Zithromax Z-Pak Causes Fatal Heart Rhythms By Jared Fink on March 21, 2013 Email this postTweet this postLike this postShare this post on LinkedIn CNN reports that the popular antibiotic drug azithromycin, marked under the brand name Zithromaz Z-Pak, can cause fatal arrhythmia in its users. Read more on how Zithromax Z-Pak causes cardiovascular death by reading the CNN report.