Zithromax (azithromycin)
Also marketed as Z-Pak. An approved treatment for Bartonellosis and Babesiosis.
Drug facts
The same compound appears under different names depending on the context. Here is how to identify Azithromycin wherever you encounter it, plus the key facts at a glance.
- Generic name
- Azithromycin
- Brand names
- Zithromax, Z-Pak
- Drug class
- Macrolide antibiotic
- How it's taken
- Usually by mouth once a day, 500mg on day 1 and then 250mg a day, paired with atovaquone for babesiosis.
A macrolide antibiotic used as first-line treatment for Bartonella infections and as part of the standard combination therapy (with atovaquone) for babesiosis.
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How Azithromycin works
Azithromycin binds to the 50S ribosomal subunit of bacteria and parasites, blocking the translocation step of protein synthesis. It concentrates inside immune cells (macrophages and neutrophils) at levels 10 to 100 times higher than in surrounding tissue, which is particularly useful against intracellular pathogens like Bartonella henselae.
Side effects and safety
Generally well tolerated. Common side effects include nausea, diarrhea, abdominal pain, and vomiting. Rare but serious risks include severe allergic reactions and severe skin reactions (such as Stevens-Johnson syndrome and DRESS), which have caused deaths, QT prolongation (abnormal heart rhythm), liver damage that can be severe or fatal, Clostridioides difficile-associated diarrhea, and worsening of myasthenia gravis.
Some studies found a higher short-term risk of death from heart problems in adults taking azithromycin than with some other antibiotics. The label also warns about a stomach blockage (pyloric stenosis) in newborns given azithromycin and about bacteria becoming resistant to it. Hearing changes have been reported at high doses.
This is not a complete list of side effects. Talk to your doctor or pharmacist about what to expect and when to seek medical attention.
Taking Azithromycin
For bartonellosis, azithromycin is typically given 500mg on day 1 followed by 250mg daily for 4 days, though LLMD protocols for chronic bartonellosis may extend treatment to weeks or months. For babesiosis, azithromycin is paired with atovaquone for at least 7 to 10 days. The usual adult dose is 500mg on day 1, then 250mg daily. Higher doses (1000mg, then 500mg daily) have been used in people with weakened immune systems or severe disease.
Availability and cost
Generic versions may be available at a lower cost. Ask your pharmacist.
Help paying for Zithromax
Several companies make generic azithromycin, so no single drugmaker program covers every version. Drugmaker copay cards can't be used with Medicare, Medicaid or TRICARE. Pick your insurance below to see which offers fit you.
No drugmaker assistance program for this medicine is published on the maker's official pages.
Good to know: Azithromycin is an older antibiotic sold as a low-cost generic by many manufacturers. There is no single manufacturer assistance program for it. Pharmacy discount programs or a pharmacist can help with cost.
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Common questions about Azithromycin
▸What is Azithromycin (Zithromax)?
A macrolide antibiotic used as first-line treatment for Bartonella infections and as part of the standard combination therapy (with atovaquone) for babesiosis.
▸How does Azithromycin work?
Azithromycin binds to the 50S ribosomal subunit of bacteria and parasites, blocking the translocation step of protein synthesis. It concentrates inside immune cells (macrophages and neutrophils) at levels 10 to 100 times higher than in surrounding tissue, which is particularly useful against intracellular pathogens like Bartonella henselae.
▸What are the side effects of Azithromycin?
Generally well tolerated. Common side effects include nausea, diarrhea, abdominal pain, and vomiting. Rare but serious risks include severe allergic reactions and severe skin reactions (such as Stevens-Johnson syndrome and DRESS), which have caused deaths, QT prolongation (abnormal heart rhythm), liver damage that can be severe or fatal, Clostridioides difficile-associated diarrhea, and worsening of myasthenia gravis. Some studies found a higher short-term risk of death from heart problems in adults taking azithromycin than with some other antibiotics. The label also warns about a stomach blockage (pyloric stenosis) in newborns given azithromycin and about bacteria becoming resistant to it. Hearing changes have been reported at high doses.
▸How is Azithromycin taken?
For bartonellosis, azithromycin is typically given 500mg on day 1 followed by 250mg daily for 4 days, though LLMD protocols for chronic bartonellosis may extend treatment to weeks or months. For babesiosis, azithromycin is paired with atovaquone for at least 7 to 10 days. The usual adult dose is 500mg on day 1, then 250mg daily. Higher doses (1000mg, then 500mg daily) have been used in people with weakened immune systems or severe disease.
▸Is Azithromycin FDA approved?
Yes, Azithromycin (Zithromax) is FDA approved (1991) for the treatment of Bartonellosis and Babesiosis.
▸What is azithromycin used for in babesiosis and bartonellosis?
Azithromycin (Zithromax) is a macrolide antibiotic used as first-line treatment for Bartonella infections and as part of the standard combination therapy with atovaquone for babesiosis.
▸How is azithromycin dosed for babesiosis and bartonellosis?
For babesiosis, azithromycin is paired with atovaquone for at least 7 to 10 days, usually 500mg on day 1 and then 250mg daily, with higher doses (1000mg, then 500mg daily) used in people with weakened immune systems or severe disease. For bartonellosis, it is typically given as 500mg on day 1 followed by 250mg daily for 4 days, though LLMD protocols for chronic bartonellosis may extend treatment to weeks or months.
▸What are the side effects of azithromycin?
Azithromycin is generally well tolerated, with nausea, diarrhea, abdominal pain, and vomiting the most common side effects. Rare but serious risks include severe allergic and skin reactions (Stevens-Johnson syndrome, DRESS), QT prolongation, liver damage that can be severe or fatal, C. difficile diarrhea, and worsening of myasthenia gravis. Some studies found a higher short-term risk of death from heart problems in adults taking azithromycin than with some other antibiotics, and hearing changes have been reported at high doses.
▸How does azithromycin work?
Azithromycin binds to the 50S ribosomal subunit of bacteria and parasites, blocking the translocation step of protein synthesis. It concentrates inside macrophages and neutrophils at levels 10 to 100 times higher than in surrounding tissue, which makes it particularly useful against intracellular pathogens like Bartonella henselae.