Using Z-Pak to Treat Strep Throat

By Terez Malka, MD
Medically reviewed checkmarkMedically reviewed
January 4, 2022

Strep throat is uncomfortable and sometimes causes significant pain.

Thankfully, it’s not usually cause for alarm and actually goes away on its own in most cases.

It can be treated with specific antibiotics to make symptoms go away about half a day more quickly and to prevent more serious complications. 

For example, Z-Pak, a brand name of the antibiotic azithromycin, can effectively treat diagnosed strep throat (as well as other bacterial infections) in those with allergies to the first-line antibiotics for strep.

However, there are some risks and precautions to keep in mind when taking this medication.

In this article, I’ll discuss strep throat and Z-pak in detail so that you understand what symptoms to watch out for and both the benefits and drawbacks of Z-pak.

This way, if you see a doctor and they prescribe the antibiotic, you know what to expect.

What Is Strep Throat?

Strep throat (also called streptococcal pharyngitis) is a bacterial infection that can cause a painful sore throat and high fever. 

Unlike sore throat symptoms caused by allergies or a viral infection, a sore throat caused by strep throat comes on quickly and is often accompanied by fever, swollen tonsils, and enlarged lymph nodes.

Keep in mind that strep throat is rarely accompanied by symptoms such as a cough, runny nose, or hoarseness.

In most cases, those are signs of a viral illness.

Though anyone can get strep throat, it’s most common in children between the ages of 5-15.

It’s also most commonly spread in late autumn and early spring, though it is possible to get it year-round.

Think you may have strep throat? Chat with a doctor today for just $73

Chat Now


Symptoms of strep throat usually appear 2-5 days after being in close contact with an infected individual or the bacteria itself.

Most cases are mild, but in some instances, strep throat can be very painful.

The most common symptoms of strep throat are:

  • Throat pain that comes on quickly
  • Pain when swallowing
  • Red, swollen tonsils
  • Small red spots on the roof of the mouth
  • White pus on the tonsils
  • Tender, swollen lymph nodes
  • Fever
  • Headache
  • Rash
  • Nausea or vomiting, particularly in younger children
  • Body aches
  • Uvulitis, or inflammation of the uvula

Importantly, a sore throat accompanied by cough, hoarseness, runny nose, or congestion is usually a sign of a viral infection and not strep throat.


Most sore throats are caused by viruses, but strep throat is a bacterial infection caused by bacteria called A Streptococcus (or group A strep).

Group A strep is contagious and can spread easily between people through close contact or touching contaminated items or surfaces. 


An official diagnosis of strep throat often requires an in-person visit with a healthcare provider.

Since most sore throats are due to viruses, it’s best to only take antibiotics if you have tested positive for strep A.

After a physical exam, the doctor or provider may perform a rapid antigen test to check for the presence of group A strep bacteria.

During the test, they gently swipe your throat with a swab to collect a sample.

The results come back quickly: Most providers are able to confirm a diagnosis and prescribe antibiotic treatment in the same visit.  

If your rapid strep test is negative, your providerr may perform a more sensitive throat culture to confirm that you don’t have strep throat.

For a throat culture, your provider swabs your tonsils and the back of your throat.

These test results often take longer than a strep test to come back, sometimes taking up to two to four days.

It is  OK to wait for those results before starting treatment.

What Is Z-Pak?

Z-Pak (azithromycin) is a macrolide antibiotic used to treat a variety of bacterial infections. 


First approved by the Food and Drug Administration (FDA) in 1991 to treat certain skin and respiratory skin infections, today Z-Pak is prescribed to treat:


Z-Pak packages generally contain six pink, film-coated tablets each containing 250 milligrams (mg) of azithromycin.

Two pills are taken on the first day, then 1 pill daily for four more days. 

How to Treat Strep Throat With Z-Pak

Z-Pak treatment for adults with strep throat is a five-day regimen of 500 mg (two 250-mg tablets) on the first day, followed by one 250-mg tablet a day for the remaining four days.

For the best results:

  • Unless recommended otherwise by your provider, you can take the pills with or without food. 
  • Try to take the medication at the same time every day. 
  • If you vomit within one hour of taking the medication, reach out to your healthcare provider immediately to determine if you should take more.

You should start to feel better within a few days of starting treatment, though your sore throat may persist for up to a week. 

Risks and Side Effects of Z-Paks

It’s important to let your doctor know about any allergies you have and medications you’re currently taking before starting Z-Pak.

The most common side effects of the medication include:

If you experience an allergic reaction or any severe side effects, seek medical advice immediately.

Examples of serious side effects include the following symptoms:

  • Fast, pounding, or irregular heartbeat
  • Dizziness
  • Fainting
  • Rash with or without fever
  • Blisters or peeling
  • Sores or swelling of the skin
  • Hives
  • Itching
  • Wheezing or difficulty breathing
  • Trouble swallowing
  • Dark-colored urine
  • Pink and swollen eyes
  • Unusual muscle weakness

You should never be given antibiotics for strep throat without a positive diagnosis via testing or evaluation by a licensed healthcare provider.

If your strep test is negative, your symptoms are likely caused by a virus, and antibiotics will not help and instead may be harmful. 

Improper use of antibiotics like Z-Pak can also contribute to antibiotic resistance.

Though azithromycin has proved strikingly effective against drug-resistant bacteria in lab and animal tests, resistance to other macrolide antibiotics (erythromycin and clindamycin) has increased in recent years, and some experts urge professional caution when prescribing azithromycin.

Think you may have strep throat? Chat with a doctor today for just $73

Chat Now

When to See a Doctor

If you or your child have any symptoms of strep throat, it’s important to speak to your provider as soon as possible so that they can start treatment and assess for complications.

Even when treated correctly, strep throat can pose some serious risks, including:

  • Meningitis
  • Kidney problems
  • Rheumatic fever
  • Pediatric autoimmune neuropsychiatric disorder (PANDAS)

If your provider confirms the diagnosis, they will pick the right antibiotic based on your symptoms and allergies.

Azithromycin is typically only used if you have allergies to other first-line options.

If you’re feeling worse two days after starting the medication, or not seeing any improvement after one week, let your provider know.

How K Health Can Help 

Did you know you can access online urgent care with K Health?

Check your symptoms, explore conditions and treatments, and if needed, text with a healthcare provider in minutes. 

K Health’s AI-powered app is based on 20 years of clinical data.

Frequently Asked Questions

Are there alternatives for Z-Pak?
The most common antibiotic treatment for strep throat is penicillin or amoxicillin. For people who are allergic to penicillin and penicillin-based antibiotics, additional possible treatments include cephalexin or other similar cephalosporins, or clindamycin.
Is Z-Pak the most effective treatment for strep throat?
No. First-line antibiotics for strep throat are penicillins and cephalosporins. Azithromycin is typically only used in those with allergies to first-line options. These can work to slightly reduce the duration and severity of symptoms, prevent rheumatic fever, and limit the spread of infection to others. Sore throat may persist for up to a week even with antibiotic treatment, but antibiotics decrease the duration of symptoms by about one day, and should prevent symptoms from worsening within 2-3 days.
Can antibiotics make strep throat worse before being better?
Antibiotics are a safe and effective treatment for strep throat, though they will not make your symptoms go away immediately- they only make symptoms improve about ½ to 1 day faster than they would resolve without the antibiotic And if your sore throat symptoms are due to a virus, antibiotics will not help and can make you feel worse. This is why it is important to be evaluated and get a strep test before starting antibiotics. If you feel your symptoms are getting worse or not improving on antibiotics within 2-3 days, contact your healthcare provider.
K Health articles are all written and reviewed by MDs, PhDs, NPs, or PharmDs and are for informational purposes only. This information does not constitute and should not be relied on for professional medical advice. Always talk to your doctor about the risks and benefits of any treatment.

Terez Malka, MD

Dr. Terez Malka is a board-certified pediatrician and emergency medicine physician.