Strep throat is an infection of your throat and tonsils, the two small tissue masses in the back of your throat. The infection can cause symptoms such as sore throat, swollen glands, fever, loss of appetite, and white spots on your tonsils.

Strep throat is caused by bacteria, so it’s treated with an antibiotic. Treatment with an antibiotic can shorten the amount of time you have strep throat symptoms and decrease the spread of infection to other people. Z-Pak is a form of the brand-name drug Zithromax. It’s an antibiotic that can treat strep throat, though it’s not a common choice for this infection.

Z-Pak is a form of the brand-name medication Zithromax, which contains the antibiotic azithromycin. Azithromycin is used to treat many different kinds of bacterial infections, including bronchitis and pneumonia. However, it’s not typically the first choice for treating strep throat. The antibiotics penicillin or amoxicillin are most often used for this condition.

That said, azithromycin or Z-Pak may be used to treat strep throat in certain cases. For instance, your doctor may prescribe it if you’re allergic to penicillin, amoxicillin, or other antibiotics that are used more often to treat strep throat.

If your doctor thinks azithromycin is a good choice for you, they may prescribe a generic version of azithromycin or a Z-Pak.

Each Z-Pak contains six 250-milligram tablets of Zithromax. You would take two tablets on the first day, followed by one tablet daily for four days. A Z-Pak typically takes at least five days to fully work, but it can start to relieve your sore throat and other symptoms on the first day you take it. If your doctor prescribes a generic version of azithromycin, your treatment may only last three days.

Be sure to take your Z-Pak or generic azithromycin exactly as your doctor prescribes. It’s important to take all of the antibiotics that you are prescribed. This is true even if you feel better before you’ve taken the full course of treatment. If you stop taking an antibiotic early, it could make the infection come back or make future infections more difficult to treat.

As with any medication, azithromycin can cause side effects. Some of the more common side effects include:

  • diarrhea
  • stomach pain
  • nausea and vomiting
  • headache

Less common and more serious side effects can also occur when taking azithromycin. Call your doctor right away if you have any of these side effects:

  • allergic reaction, with symptoms such as skin rash or swelling of your lips or tongue
  • yellowing of your skin or the whites of your eyes
  • easy bleeding or bruising
  • severe diarrhea or diarrhea that doesn’t go away
  • heart rhythm problems

If you have strep throat, your doctor will prescribe the antibiotic that they think is the most appropriate for you. In most cases, this would be penicillin or amoxicillin. However, some people are prescribed a Z-Pak or generic azithromycin. If you have further questions about either medication, be sure to ask your doctor. Your questions might include:

  • Is this the best drug to treat my strep throat?
  • Am I allergic to penicillin or amoxicillin? If so, are there any other drugs I should avoid?
  • What should I do if my throat still hurts after I finish my medication?
  • What can I do to relieve my sore throat while I wait for the antibiotic to work?

Q:

What is a drug allergy?

A:

If your doctor prescribes azithromycin or Z-Pak for your strep throat, it may be because you’re allergic to the medications more often used for this condition. With a drug allergy, your body thinks a certain drug is a foreign invader. This causes your immune system, which fights disease, to try to get rid of the drug. This can result in a serious reaction such as anaphylaxis, which can cause irregular heartbeat, trouble breathing, and even death.

Drug allergies are rare. Often, when people think they’re allergic to a drug, they’re simply having side effects from the drug. To find out if you have a drug allergy, talk to your doctor. They may refer you to an allergist to do a full assessment of your reaction to a drug. For more information, read the complete overview on drug allergies.

Healthline Medical TeamAnswers represent the opinions of our medical experts. All content is strictly informational and should not be considered medical advice.