Z-Pak Dosages for Kids and Adults: Your GoodRx Guide

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. These include strep throat, pneumonia, and ear infections. Azithromycin dosages are the same for many people. So the prepackaged, ready-to-use Z-Pak is a convenient way to prescribe, fill, and take the medication. But a few things can affect your Z-Pak dosage, such as your age and other medications you take.

Here, we’ll review the recommended Z-Pak dosages for adults and children. Keep in mind that azithromycin comes in other forms with different dosing schedules. So be sure to follow your prescriber’s instructions carefully.

What’s the typical Z-Pak dosage for adults?

A Z-Pak comes as a blister pack that holds 6 tablets. Each tablet contains 250 mg of azithromycin. You’ll take a Z-pak for 5 days, as follows:

• Day 1: 2 tablets (500 mg) as a single dose

• Days 2 to 5: 1 tablet (250 mg) per day

Azithromycin is also available as loose tablets. So in some cases, you may receive a bottle of 6 tablets instead of a dose pack. But the instructions will be the same. Be sure to read the label carefully to ensure you’re taking the medication as directed.

Try to take your Z-pak doses around the same time each day. You can take azithromycin with or without food. But if you experience diarrhea or an upset stomach after taking it, try taking your next dose with food to help minimize these side effects.

You may start to feel better after a few days of taking azithromycin. But you should still continue to take the full course of your antibiotic. Stopping a Z-Pak early can lead to an undertreated infection and antibiotic resistance. This means a Z-Pak may not work as well for you the next time you take it for an infection.

Good to know: The Z-Pak is different from the Tri-Pak, which holds 3 tablets that contain 500 mg of azithromycin each. The recommended Tri-Pak dosage is 1 tablet daily for 3 days.

What’s the typical Z-Pak dosage for children?

Azithromycin can also treat bacterial infections in children ages 6 months and older. But for tonsil infections and strep throat, it isn’t recommended for children under age 2.

The azithromycin dosage for children is based on your child’s body weight. Children who weigh 110 lbs (50 kg) or more can follow the adult Z-pak dosage. But in most cases, children are prescribed azithromycin suspension (liquid). The suspension comes in two doses: 100 mg/5 mL and 200 mg / 5 mL.

There isn’t a liquid version of a Z-Pak. But your prescriber may recommend a similar dosing schedule using the suspension, with a higher dose on the first day and a lower dose for Days 2 to 5.

For example, a typical dose of azithromycin for a child with an ear infection is 10 mg per kilogram of body weight on the first day, followed by 5 mg per kilogram of body weight on Days 2 to 5. For a child weighing 44 lbs (20 kg), this would equate to a 200 mg dose on Day 1 and a 100 mg dose on Days 2 to 5. For the azithromycin suspension containing 200 mg / 5 mL, this means you would measure a 5 mL dose on Day 1 followed by 2.5 mL doses on Days 2 to 5.

This may seem complex, but rest assured your healthcare team will make all the necessary calculations. Your prescriber and pharmacist will also review the exact dosage measurement for your child with you when it’s prescribed. But don’t hesitate to ask if any questions arise during treatment.

Are there any Z-Pak dosage adjustments for medical conditions?

There aren’t any medical conditions that require Z-Pak dose adjustments. But caution is needed when azithromycin is prescribed to people living with certain conditions, such as liver and heart problems.

Before taking azithromycin, tell your prescriber if you have a history of liver problems. A Z-Pak isn’t recommended if you have a history of severe liver dysfunction or jaundice (yellowing of the skin or eyes).

Azithromycin can also cause long QT syndrome. This is a condition in which your heart takes more time to reset during beats. This isn’t common, but it can be life-threatening. The risk of QT prolongation is higher when azithromycin is combined with certain health conditions, such as other heart rhythm problems, or medications such as amiodarone (Pacerone).

You can help prevent these interactions by telling your healthcare team about your health history and the medications you’re taking. But if you experience a fast or irregular heartbeat, chest pain, or dizziness while taking a Z-Pak, seek medical care right away.

What happens if you miss a dose of azithromycin?

Taking your antibiotic consistently helps maximize its effectiveness. So if you miss a dose of your Z-Pak, take it as soon as you remember. If it’s close to the time of your next scheduled dose, it’s best to skip the missed dose and take your next dose as planned. Don’t double up on doses to make up for the one you missed. But you should still take all the tablets in the Z-Pak. You may need to add an extra day onto your original schedule if you miss a dose.

Taking your antibiotic at the same time every day is a helpful way to remember to take it consistently. There are also tools that can help you remember to take it on time and as planned. For example, setting an alarm for a certain time of day (like after a meal) can be helpful. Medication reminder apps are also useful options.

What should you do if you take too much azithromycin?

Since it comes in a blister pack, it should be relatively easy to tell if you’ve already taken your Z-Pak dose for the day. But if you take an extra dose by mistake, it’s unlikely to cause any harm. In fact, higher azithromycin doses (up to 2 g) are prescribed for certain infections. But you may experience more side effects after an extra dose, such as diarrhea, nausea, and stomach pain.

If you or your child takes too much azithromycin, it’s best to contact your prescriber as a precaution. They can determine next steps and guide you appropriately. You can also contact Poison Control online or at 1-800-222-1222. But if you’re experiencing severe symptoms, it’s best to seek emergency care right away.

How to save on your Z-Pak

Z-Pak is a nickname for the prepackaged form of azithromycin. It’s available as a brand-name and generic medication. GoodRx can help you save over 80% off the average retail price of the generic version.

The price of a generic Z-Pak (azithromycin) is as low as $9.38 at certain pharmacies with a free GoodRx discount. And the price of a 15 mL bottle of 200 mg / 5 mL generic azithromycin suspension is as low as $12.72 with GoodRx.

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Written by:

Cassandra Pardini, PharmD, MS

Cassandra Pardini has been a freelance medical writer for 7 years. In that time, she has concentrated on publishing articles on medication-related information for healthcare professionals and patients.

Edited by:

Stacia Woodcock, PharmD

Stacia Woodcock, PharmD, is a pharmacy editor for GoodRx. She earned her Doctor of Pharmacy degree from the University of Kentucky and is licensed in New York and Massachusetts.

Reviewed by:

Joshua Murdock, PharmD, BCBBS

Joshua Murdock, PharmD, BCBBS, is a licensed pharmacist in Arizona, Colorado, and Rhode Island. He has worked in the pharmacy industry for more than 10 years and served as a pharmacy editor for GoodRx.

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