Quick Answer: Azithromycin — sold as Zithromax or the Z-Pak — is a macrolide antibiotic prescribed to treat bacterial infections including pneumonia, chlamydia, strep throat, and sinusitis. Azithromycin pills in Europe, with brand name Sumamed. Azithromycin, sold under the brand names Zithromax (in oral form) and Azasite (as an eye drop), is an antibiotic medication used to treat several bacterial infections. [9]. Learn about Z-Pak (azithromycin), a commonly prescribed antibiotic for bacterial infections. Discover its uses, dosage, side effects, and more. How does a Z‑Pak work so quickly? A Z‑Pak gives you a strong initial dose—two tablets on Day 1 and one tablet each on Days 2–5. Even though you stop after five days, the medication keeps working long after because it stays active in the body for over two days at a time. What is Zithromax Z-Pak? Zithromax Z-Pak is used to treat many different types of infections caused by bacteria, including infections of the lungs, sinus, throat, tonsils, skin, urinary tract, cervix, or genitals. Zithromax Z-Pak may also be used for purposes not listed in this medication guide. Overview: Azithromycin is an antibiotic that is used to treat certain bacterial infections. It works by stopping certain types of bacteria from making proteins they need to grow and multiply. It contains six 250 mg tablets of azithromycin taken over 5 days. Z-Paks can treat several bacterial infections, ranging from pneumonia to skin infections. Common Z-Pak side effects include diarrhea, nausea, and stomach pain. Z-Paks are widely available as a lower-cost generic. Azithromycin 5 Day Dose Pack is used to treat many different types of infections caused by bacteria, including infections of the lungs, sinus, throat, tonsils, skin, urinary tract, cervix, or genitals. Azithromycin 5 Day Dose Pack may also be used for purposes not listed in this medication guide. Z-Pak is a prescription antibiotic with six 250 mg tablets of azithromycin in a blister pack. It can treat several bacterial infections, including strep throat, ear infections, and pneumonia. Designed for and by long-distance backpackers, they deliver the all-day comfort, mobility, and trail-tested functionality needed for months on trail, while offering the streamlined versatility minimalist travelers want for flights, city walking, and fast-moving itineraries.