Azithromycin — Practical Guide for Families

Azithromycin is a common antibiotic you’ve probably heard of. Doctors use it for many bacterial infections: certain chest infections, ear infections, strep throat, some skin infections, and sexually transmitted infections like chlamydia. It fights bacteria, not viruses, so it won’t help with colds or the flu.

How it works is simple: azithromycin interferes with bacterial protein production so the bug can’t grow. That makes symptoms improve and helps your immune system clear the infection. Because it’s powerful and widely used, sticking to the right dose and duration matters to avoid side effects and resistance.

Common doses you’ll see

Adults often get azithromycin in a short course. A typical “Z‑Pak” is 500 mg on day 1, then 250 mg once daily on days 2–5. Some prescriptions use 500 mg once daily for 3 days. For uncomplicated chlamydia, doctors commonly give a single 1 g (1000 mg) dose. Children’s doses depend on weight—always follow the exact prescription from your pediatrician.

Take tablets with water. If your doctor tells you to space it from antacids, do it—antacids with aluminum or magnesium can lower how much medicine your body absorbs, so take azithromycin at least 1–2 hours before or after those antacids if advised.

Side effects, interactions, and safety tips

The most common side effects are stomach-related: nausea, diarrhea, and occasional stomach pain. If you get a rash, facial swelling, trouble breathing, fainting, or severe yellowing of the skin or eyes, seek emergency care—those can be signs of a serious allergic reaction or liver problem.

Azithromycin can affect heart rhythm in people with certain conditions or who take other drugs that lengthen the QT interval. If you have a history of arrhythmias, low potassium, or are on medicines for the heart, tell your doctor. Also mention blood thinners like warfarin—your doctor may watch your INR more closely while you’re on azithromycin.

Don’t stop mid-course unless your prescriber tells you to. Stopping early can leave bacteria partly treated and encourage resistance. Also, don’t expect azithromycin to work for viral infections; ask your clinician if an antibiotic is really needed.

If you’re pregnant or breastfeeding, talk with your clinician—azithromycin is used in pregnancy when needed, but your provider will weigh risks and benefits for your situation.

Buying online? Only use pharmacies that require a prescription, show clear contact info, are licensed, and offer a pharmacist you can talk to. Avoid sites that sell antibiotics without a prescription or have suspiciously low prices. Secure checkout (HTTPS) and visible customer reviews help, but when in doubt call the pharmacy or ask your local pharmacist for advice.

If you’re unsure whether azithromycin is right for you or your child, call your healthcare provider. They can confirm the diagnosis, pick the correct dose, and flag any drug interactions or safety concerns specific to your health.