What Is a Z-Pak and Is It a Good Choice for Treating Infections?

The Z-Pak (or Zithromax Z-Pak) is an antibiotic medication that unfairly gets a bad rap. True, it’s often incorrectly prescribed for sinus infections caused by viruses, which don’t respond to antibiotics. But Z-Paks offer many benefits we shouldn’t forget. Here are some of the reasons why they’re still worth considering.

What is a Z-Pak?

The Z-Pak is a prescription package that contains six azithromycin (Zithromax) tablets that are typically taken over 5 days. Your specific dosage will depend on your diagnosis. Azithromycin is a popular antibiotic medication that treats a variety of health conditions. It works by stopping the growth of certain types of bacteria. It does not work against viruses.

Z-Paks are easy to use, generally affordable, and highly effective. Azithromycin is quickly absorbed when you take it by mouth. It easily enters your body tissues so it can fight the bacteria causing your infection and stay active for a long time. 

Other antibiotics in its class, like clarithromycin, have many drug interactions. Azithromycin doesn’t have the same interactions, but there are a few to know about. Examples include statins, heart rhythm medications, and antacids.

Z-Paks for strep throat, pneumonia, bronchitis, and more

A Z-Paks is typically prescribed for convenience. It contains the exact number of tablets you’d need for certain infections and health conditions, at the right strength. Here are four examples:

1. Strep throat: Azithromycin is FDA-approved to treat strep throat (also known as streptococcal pharyngitis). Penicillin antibiotics are usually the first choice of treatment for this infection. But a Z-Pak may be a good option if you have a penicillin allergy.

2. Skin and soft tissue infections: Infections of the skin or soft tissues — like muscles and tendons — commonly caused by Staph and Strep bacteria can be treated with Z-Paks. 

3. Community-acquired pneumonia: For mild cases of pneumonia that are acquired out in the community (and not contracted in a hospital), Z-Paks are a useful option.

4. Acute worsening of chronic bronchitis: People with chronic bronchitis can sometimes develop a bacterial infection that causes their symptoms to worsen. This infection can be treated with either a Z-Pak or a Tri-Pak. The Tri-Pak contains three 500 mg tablets instead of the six 250 mg tablets found in a Z-Pak.

Promotion disclosure

Azithromycin

Avg retail price

$41.66(Save 80.29%)

GoodRx discount

$8.21

See all discounts

How it works

Use GoodRx to find medications, pharmacies, and discounts.

GoodRx discounts can help you pay less for your prescription.

Bring your free coupon or savings card to the pharmacy.

Can Z-Paks help treat or prevent other conditions?

Azithromycin, the active ingredient in Z-Paks, is actually used to treat many more conditions. In other strengths and forms beyond the 6-tablet Z-Pak, azithromycin is often prescribed to prevent or treat other conditions, including:

1. Acute bacterial sinusitis: Penicillin antibiotics are a first-choice treatment for acute bacterial sinusitis. But azithromycin is a good option if you’re allergic to those medications. It’s typically treated with a Tri-Pak, where you take one tablet daily for 3 days.

2. Chlamydia: Azithromycin can be used to treat the sexually transmitted infection, chlamydia. The usual dosage is a single 1 gram dose of azithromycin. One dose and done.

3. Traveler’s diarrhea: According to the CDC, azithromycin may be used to treat moderate traveler’s diarrhea. And it’s the preferred treatment for severe cases. 

4. Certain urethra infections: A single 1-gram dose of azithromycin can treat certain urethra infections (urethritis) in men. Doxycycline is another option, but you’d have to take it for 7 days to get the same effect.

5. Chronic lung diseases: For folks with chronic obstructive pulmonary disease (COPD), researchers found that daily 250 mg doses of azithromycin reduced episodes of exacerbations (sudden worsening symptoms) and improved quality of life. Some healthcare providers may prescribe it off-label for this use.

6. Prevention of certain infections in people living with HIV/AIDS: Azithromycin is FDA approved to prevent and treat infections caused by M. avium-intracellulare (MAC) in people living with HIV/AIDS. MAC is a microorganism related to the bacteria that cause tuberculosis.

What is the typical Z-Pak dosage?

Z-Paks are available as a package containing six tablets, with 250 mg of azithromycin each. You’ll start by taking 2 tablets on the first day as a single dose, followed by 1 tablet on days 2 through 5. For children, the dosing is typically based on their weight and what condition is being treated. 

There’s a similar product called the Tri-Pak that comes with 3 tablets of azithromycin, each containing 500 mg. With this product, you typically take one tablet daily for 3 days.

It’s important to take your Z-Pak as prescribed. Try to take it at the same time every day you’re supposed to take it until you finish the entire prescription regimen. Not completing your treatment can increase the risk that your infection returns. What’s more, azithromycin may stop working as well against the bacteria, which is known as antibiotic resistance. This makes the bacterial infections more difficult to treat.

Are there any side effects associated with Z-Paks?

As with many medications, you may experience side effects while taking a Z-Pak. Most commonly, these include:

• Diarrhea

• Nausea

• Abdominal pain

• Vomiting

Higher azithromycin doses are typically associated with a greater risk of side effects. In other words, a single 1-gram dose may be more likely to cause side effects than lower doses over a few days, like with a Z-Pak.

Other more serious side effects are also possible. This includes liver damage and serious skin reactions, like Stevens-Johnson syndrome. Compared to other antibiotics, a Z-Pak may be less likely to cause Clostridium difficile (“C. diff”) infection, but it can still happen. C. diff infections are very contagious and can cause watery diarrhea, stomach cramps, and fever.

Z-Paks and other azithromycin products also have a warning of heart rhythm problems. More on that next.

Do Z-Paks come with any heart risks?

Azithromycin has been shown to prolong the QT interval. This means it takes more time for your heart to reset between beats. A long QT interval can increase the risk of potentially life-threatening abnormal heart rhythms. In 2013, the FDA put out a warning about this risk.

However, a 2017 population-based study of over 14 million people examined this risk with azithromycin. It found no increased risk of ventricular arrhythmia compared to another common antibiotic, amoxicillin. Even so, it’s important to be aware of this potential risk. Let your healthcare provider know right away if you start experiencing lightheadedness, blurred vision, or fainting.

Certain health conditions and medications may increase the risk of long QT interval when combined with azithromycin. Your healthcare provider will be able to assess your risk and recommend appropriate alternatives, if needed.

How to save on Z-Pak

There are ways to save on Z-Pak, which is available as both a brand-name and generic medication. GoodRx can help you save over 80% off the average retail price of the generic version. Generic Z-Pak’s price at certain pharmacies is less than $10 with a free GoodRx discount.

Why trust our experts?

Written by:

Sharon Orrange, MD, MHS

Sharon Orrange, MD, MHS, is the director of wellness and preventative care at the Ellison Institute of Technology and an associate professor of clinical medicine in the Division of General Internal Medicine at the University of Southern California's Keck School of Medicine.

Edited by:

Alyssa Billingsley, PharmD

Alyssa Billingsley, PharmD, is the director of pharmacy content for GoodRx. She has over a decade of experience as a pharmacist and has worked in clinical, academic, and administrative roles.

Reviewed by:

Christina Aungst, PharmD

Christina Aungst, PharmD, is a pharmacy editor for GoodRx. She began writing for GoodRx Health in 2019, transitioning from freelance writer to editor in 2021.

Our editorial standards

Meet our experts