Can You Take A Z-Pak If You Have A Penicillin Allergy?
In our latest question and answer, the pharmacist discusses the safety of taking a Z-Pak if you have a penicillin allergy.
I was told that I had an allergic reaction to penicillin when I was a child. I have it on my medical record. I was just given a Zpak. Is it ok to take due to my penicillin allergy?
Oct 04, 2022- Azithromycin (Z-Pak) is typically safe to take if you have a penicillin allergy because these antibiotics belong to different drug classes with no cross-reactivity between them. Studies have confirmed that azithromycin is a valid alternative for patients who cannot take penicillin or cephalosporins. Always inform your doctor and pharmacy about your penicillin allergy so they can prescribe an appropriate alternative antibiotic.
Answer
Thanks so much for reaching out! I'll provide some more detail in the sections below, but yes, azithromycin (Z-Pak) is typically fine to take if you have a documented penicillin allergy. These antibiotics are in different drug classes and studies have shown there is no cross-reactivity between them.
Azithromycin And Penicillin Are Different Types Of Antibiotics
As mentioned, the two antibiotics in question here are in different drug classes.
Penicillin is a penicillin-type antibiotic, while azithromycin is a macrolide antibiotic.
While it is true that some sensitivities/allergies can cross over between drug classes (penicillin-type drugs and cephalosporins are a good example of that). Several studies have confirmed that if a patient is allergic to penicillin, a macrolide, like azithromycin, may be a good choice:
This antibiotic [azithromycin] is therefore a valid alternative to penicillin and/or cephalosporin in patients allergic to these two drugs.
Depending on what you are being treated for, you likely have a number of antibiotic options if you can't take penicillin (e.g. Macrolides, tetracycline, fluoroquinolones, sulfamethoxazole etc...). Be sure to let your doctor and pharmacy know of your allergies, so if penicillin were to be prescribed, your allergy can be noted and an alternative antibiotic be given.
Final Words
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References & sources
- [Safety of azithromycin in patients allergic to penicillin and cephalosporin] — PubMed
- A randomized, comparative pilot study of azithromycin versus benzathine penicillin G for treatment of early syphilis — PubMed
- Penicillin susceptibility and macrolide-lincosamide-streptogramin B resistance in group B Streptococcus isolates from a Canadian hospital — PubMed
Glossary — Terms in This Answer
- Cross-reactivity
- When your body's allergic reaction to one drug also occurs with a different drug because they share similar chemical structures.
- Drug classes
- Groups of medications that are organized together based on how they work and their chemical composition.
- Macrolide antibiotic
- A type of antibiotic that works by stopping bacteria from making proteins they need to survive.
- Penicillin-type antibiotic
- An antibiotic derived from or similar to penicillin that kills bacteria by breaking down their cell walls.
- Cephalosporins
- A class of antibiotics similar in structure to penicillin that can sometimes cause allergic reactions in people allergic to penicillin.
- Tetracycline
- A broad-spectrum antibiotic that stops bacterial growth by preventing them from making proteins.
- Fluoroquinolones
- A class of antibiotics used to treat various bacterial infections by interfering with bacterial DNA.
- Sulfonamide
- A type of antibiotic containing sulfur compounds that stops bacteria from reproducing.
Dr. Brian Staiger, PharmD
Doctor of Pharmacy, board certified clinical pharmacist (BCPS), American Herbalist Guild, Medication Therapy Management certified
Brian Staiger, PharmD, BCPS, is a licensed pharmacist with more than 13 years of experience across retail pharmacy, clinical pharmacy, medication safety, pharmacy program development, and healthcare administration. He is the founder of HelloPharmacist.com, where he helps patients...
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