Azithromycin Dosage: What You Need to Know

Azithromycin is a common antibiotic that treats many infections, from sore throats to chest infections. Getting the right dose is key to clearing the bug and avoiding side effects. Below you’ll find the most used dosing schedules, when to adjust the amount, and simple tips if you miss a pill.

Standard adult dosing

For most adult infections, doctors prescribe a 5‑day regimen that looks like this:

• Day 1: 500 mg (usually two 250 mg tablets) taken once.
• Days 2‑5: 250 mg taken once daily.

This “loading dose” on day 1 helps the drug build up fast, so you feel better sooner. Common conditions that use this schedule include:

• Strep throat
• Sinus infections
• Community‑acquired pneumonia
• Skin infections

If you’re treating a sexually transmitted infection like chlamydia, the usual adult dose is a single 1 g (1000 mg) tablet taken once. No follow‑up pills are needed for that infection.

People with liver disease may need a lower dose because azithromycin is processed in the liver. Your doctor will decide the exact amount.

Kids and special cases

Children get a dose based on their weight, measured in milligrams per kilogram (mg/kg). The typical range is 10‑12 mg/kg once daily for 3‑5 days. For example, a 20‑kg child would take about 200‑240 mg per day.

For pediatric ear infections, doctors often give a single 30 mg/kg dose on day 1, followed by 10‑12 mg/kg on days 2‑5. The exact schedule depends on the infection type and how severe it is.

If the child is under 6 months old, many doctors avoid azithromycin unless there’s a strong reason, because safety data are limited.

Special situations that change the dose:

• Kidney problems: No major adjustment needed, but doctors watch for buildup.
• Pregnancy: Azithromycin is usually considered safe, but only take it if your doctor says so.
• Drug interactions: Antacids, certain heart meds, and some blood thinners can affect how azithromycin works. Tell your doctor about all medicines you’re using.

Missed a dose? Take it as soon as you remember, unless it’s almost time for the next dose. In that case, skip the missed one and continue with the regular schedule. Never double up.

Always finish the entire prescription, even if symptoms improve. Stopping early can let the infection return or become resistant.

Lastly, watch for side effects. Most people only get mild stomach upset or a brief rash. If you notice severe diarrhea, vomiting, or a fast heartbeat, call your doctor right away.

With the right dose and a few simple habits, azithromycin can clear most infections quickly and safely.