What Is Azithromycin?

Azithromycin is a macrolide antibiotic used to treat a wide range of bacterial infections, including pneumonia, bronchitis, sinus infections, ear infections, strep throat, and certain sexually transmitted infections like chlamydia.

It's sold under the brand name Zithromax (manufactured by Pfizer) and is widely available as an affordable generic. You've probably heard it called a Z-Pak or Z-Pack — that's the popular 5-day tablet course. Azithromycin is not a controlled substance and doesn't require any special prescribing authorization.

It's one of the most commonly prescribed antibiotics in the U.S. due to its short treatment course, once-daily dosing, and broad effectiveness against common bacteria.

What Is Azithromycin Used For?

Azithromycin is FDA-approved to treat the following conditions:

• Community-acquired pneumonia — A common lung infection acquired outside of hospitals.
• Acute bacterial exacerbations of COPD — Flare-ups of chronic obstructive pulmonary disease caused by bacteria.
• Acute bacterial sinusitis — Sinus infections caused by bacteria.
• Pharyngitis and tonsillitis — Strep throat (as a second-line option for patients allergic to penicillin).
• Uncomplicated skin infections — Certain skin and soft tissue infections.
• Urethritis and cervicitis — Chlamydia and gonorrhea infections.
• Genital ulcer disease (chancroid)
• Acute otitis media — Middle ear infections, especially in children.
• MAC disease — Prevention and treatment of Mycobacterium avium complex in HIV patients.

Doctors also prescribe Azithromycin off-label for traveler's diarrhea, pertussis (whooping cough), babesiosis, certain dental infections, and as maintenance therapy in cystic fibrosis patients.

To learn how Azithromycin actually fights these infections, read our article on how Azithromycin works.

How Is Azithromycin Taken?

Azithromycin comes in several forms:

• Oral tablets: 250 mg, 500 mg, and 600 mg
• Oral suspension (liquid): 100 mg/5 mL and 200 mg/5 mL — commonly used for children
• Extended-release suspension (Zmax): A single 2-gram dose
• IV injection: 500 mg — used in hospital settings for severe infections
• Ophthalmic drops (Azasite): 1% — for bacterial eye infections

Note: The 1-gram powder packets were permanently discontinued by Pfizer in June 2024.

The Most Common Regimen: The Z-Pak

The classic Z-Pak contains six 250-mg tablets taken over 5 days:

• Day 1: Two tablets (500 mg total)
• Days 2-5: One tablet per day (250 mg)

Total dose: 1,500 mg over 5 days. That's it — no refills, no extended courses.

How to Take It

• Tablets can be taken with or without food.
• The oral suspension should be taken on an empty stomach (1 hour before or 2 hours after eating).
• Do not take antacids (aluminum or magnesium-based) within 2 hours of Azithromycin, as they can reduce absorption.
• Complete the full course even if you feel better after a day or two. Stopping early can lead to antibiotic resistance.

For more details on drug interactions and what to avoid, see our guide on Azithromycin drug interactions.

Who Should Not Take Azithromycin?

Azithromycin is not safe for everyone. You should not take it if you have:

• A known allergy to Azithromycin, Erythromycin, Clarithromycin, or any macrolide or ketolide antibiotic.
• A history of cholestatic jaundice or liver dysfunction from a previous course of Azithromycin.

Use with caution if you have:

• Liver disease
• Heart rhythm problems or a prolonged QT interval
• Low potassium or magnesium levels
• Myasthenia gravis (can worsen symptoms)

Azithromycin is classified as Pregnancy Category B — it's considered relatively safe during pregnancy, though you should always discuss risks with your doctor. It is excreted in breast milk.

For a complete list of side effects, read our article on Azithromycin side effects.

How Much Does Azithromycin Cost?

Azithromycin is one of the most affordable antibiotics available:

• Generic Z-Pak (cash price): $10 to $40 at most pharmacies
• With a discount coupon (GoodRx, SingleCare): As low as $4 to $6
• With insurance: Typically a $0 to $10 copay — it's a Tier 1 preferred generic on virtually all plans
• Brand-name Zithromax: $80 to $300+, but there's rarely a reason to use brand over generic

There's no active manufacturer savings program because the generic is already so affordable. However, patients facing financial hardship can access Pfizer RxPathways, NeedyMeds, and RxAssist for additional help.

For the full breakdown of how to save, check out our guide to Azithromycin coupons, discounts, and patient assistance.

Is Azithromycin Hard to Find?

Azithromycin tablets are generally in good supply. The oral suspension has experienced intermittent shortages, particularly during the 2022-2023 respiratory illness surge. The 1-gram powder packets are permanently discontinued.

If you're having trouble finding your prescription, see our guides on finding Azithromycin in stock near you and checking pharmacy stock without calling. Or visit Medfinder to search pharmacy availability directly.

Final Thoughts

Azithromycin is a widely used, well-studied, and affordable antibiotic that treats a broad range of bacterial infections. Its short 5-day course, once-daily dosing, and low cost make it a go-to option for doctors and patients alike.

If you need to find a doctor who can prescribe it, read our guide to finding a prescriber near you. If you can't fill your prescription, explore alternatives to Azithromycin.

Ready to find a pharmacy near you? Visit Medfinder.