Azithromycin dosing: clear, practical tips
Need to know how to take azithromycin? Start here. I’ll cover the common doses for adults and kids, a few special cases, and quick safety tips so you know what to expect. This is a practical guide — always double-check with your prescriber before changing anything.
Common dosing schedules
For adults, the most familiar plan is the 5-day "Z‑Pak": 500 mg on day 1, then 250 mg once daily on days 2–5. Another common option is 500 mg once daily for 3 days for some respiratory infections. For certain sexually transmitted infections like uncomplicated chlamydia, a single 1 g (1000 mg) oral dose is often used — but only when a clinician recommends it.
Kids get doses by weight. A typical pediatric schedule is 10 mg/kg on day 1, followed by 5 mg/kg once daily on days 2–5 (usually capped by adult tablet strengths). Liquid formulations make this easier; follow the exact mg/kg your doctor prescribes. Never guess a child’s dose.
IV dosing, duration, and variations
Severe infections or hospitalized patients might get azithromycin intravenously. A common IV dose is 500 mg once daily. Treatment length depends on the infection and how well they respond — sometimes 3 days, sometimes longer. Your doctor will decide based on labs and symptoms.
Where it’s used: azithromycin treats respiratory infections, some ear infections, certain skin infections, and specific STIs. It’s not the right antibiotic for everything — culture results or guidelines may point to a different choice.
How to take it: azithromycin can be taken with or without food, though some people find it gentler after a meal. Finish the prescribed course unless your doctor tells you otherwise — stopping early can let bacteria return.
Missed dose? Take it as soon as you remember. If it’s almost time for the next dose, skip the missed one. Don’t double up to catch up.
Storage: keep tablets or liquid at room temperature, away from heat and direct sunlight. Follow the pharmacy label for how long to keep mixed liquid formulations.
Safety & special situations: Azithromycin can cause stomach upset, diarrhea, or a metallic taste. Rarely, it can affect heart rhythm (QT prolongation) — so tell your doctor if you take heart meds or have a history of irregular heartbeat. People with severe liver problems need extra caution because azithromycin is processed by the liver. If pregnant or breastfeeding, check with your provider; azithromycin is sometimes used but only when benefits outweigh risks.
Final note: this guide explains common doses, not a prescription. Always follow your clinician’s orders and ask questions if you’re unsure. If you notice severe side effects — chest pain, fainting, severe allergic reaction, or extreme diarrhea — seek medical help right away.
