Azithromycin — What It Treats, How to Take It, and Safe Buying Tips

Azithromycin is a common antibiotic doctors prescribe because it often works fast and needs only a short course. You’ve probably seen it sold as Z-Pak or generic azithromycin. It fights many bacterial infections by stopping bacteria from making the proteins they need to grow. That makes symptoms fade and infections clear.

How people take azithromycin

There are a few typical dosing patterns you’ll see. For many respiratory infections a common approach is 500 mg on day 1 then 250 mg once daily for four more days (the 5-day Z‑Pak style). Another common option is 500 mg once daily for three days for certain infections. For uncomplicated chlamydia, a single 1 g dose is often used. Always follow your prescriber’s exact instructions — dose depends on the infection, age, and kidney or liver health.

Take azithromycin with or without food; a light meal can reduce stomach upset. Avoid taking antacids that contain aluminum or magnesium at the same time — separate them by at least two hours, as they can lower azithromycin absorption.

Side effects, risks, and interactions

The most common side effects are stomach-related: nausea, diarrhea, and abdominal pain. Most people tolerate azithromycin well, but watch for allergic reactions (rash, swelling, breathing trouble) and get urgent help if they occur. Less common but serious risks include irregular heartbeat or fainting — azithromycin can affect heart rhythm, especially in people with existing heart issues or when combined with other medicines that prolong QT interval (certain antidepressants, antipsychotics, and some antiarrhythmics).

Azithromycin interacts less with liver enzymes than some other macrolides, but interactions still happen. Tell your doctor if you take blood thinners, heart meds, or drugs for seizures. Pregnant or breastfeeding? Speak to your clinician — azithromycin is sometimes used, but decisions are individual.

Finish the full course unless your doctor tells you otherwise. Stopping early can leave some bacteria alive and lead to resistance — then the antibiotic might not work next time.

Thinking of buying azithromycin online? Be careful. Legitimate pharmacies will ask for a prescription, list a real business address and phone number, and display clear shipping and return policies. Avoid sites that sell prescription drugs without asking for a prescription, offer extremely low prices, or use fake seals. Look for independent customer reviews and pharmacy verification when possible.

Store tablets at room temperature away from heat and moisture. Keep a record of lot numbers and expiry dates when you order online. If a package looks tampered with or pills look different than expected, don’t use them — contact the pharmacy and your prescriber.

If you have questions about whether azithromycin is right for you, or about dosing and interactions, contact a healthcare professional. Getting the right drug, dose, and duration matters — and it’s the best way to get well without creating new problems.