There’s a good chance you’ve been prescribed, or at least heard of, a Z-Pak. It contains a “pack” or blister card with 6 tablets of azithromycin (Zithromax). This is a macrolide antibiotic that has been around for decades and is generally well tolerated. A Z-Pak can treat a variety of mild-to-moderate bacterial infections. Azithromycin is used to treat many different types of infections caused by bacteria, such as respiratory infections, skin infections, ear infections, eye infections, and sexually transmitted diseases. Azithromycin may also be used for purposes not listed in this medication guide. The standard Z-pack (azithromycin) dosage for adults with common bacterial infections is 500 mg on day 1, followed by 250 mg once daily on days 2 through 5, with specific variations based on the type of infection being treated. 1 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. The Z-Pack (azithromycin) is a five-day antibiotic prescribed for mild to moderate bacterial infections, most commonly sinus infections, bronchitis flare-ups, and certain types of pneumonia. It comes as a pack of six pills: 500 mg on the first day, then 250 mg daily for four more days. 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. Specifically designed for long-distance hikers, our ultralight backpacks help you crush miles on any trail. Take our Backpack Recommendation Quiz to find the best backpack for you. Designed for advanced hikers who want their frameless pack to move fast and work hard, the Nero Pro takes the same streamlined, frameless philosophy that makes the Nero Classic a go-to for minimalists, long-distance hikers, and elevates it to technical territory. 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..