Zithromax (Azithromycin), commonly marketed as the "Z-Pack," was the subject of a study published in the New England Journal of Medicine yesterday. The study found "a small increase in cardiovascular deaths, and in the risk of death from any cause, in persons treated with a 5-day course of azithromycin (Zithromax) compared to persons treated with amoxicillin, ciprofloxacin, or no drug."

On reviewing the findings of this study, the FDA issued a warning notice to consumers, particularly consumers with heart problems, taking, or planning to take, Zithromax.

Zithromax is one of the top selling antibiotics in the nation. According to ABC News, the antibiotic was prescribed to over 55 million people, raking in $464 million in sales.

While some researchers are saying that, "The chances of dying crossing the street are greater than from taking this antibiotic," others say that there is no noticeable benefit of taking Zithromax compared to other, perhaps safer, antibiotics.