Azithromycin

Infections

Also known as Zithromax, Z-Pak

Azithromycin treats certain chest infections, sinus and ear infections, strep throat, and some sexually transmitted infections. The course is unusually short because the drug hangs around in your tissues and keeps fighting for days after your last dose — so a few pills really do carry a full punch. It's an antibiotic, so it won't touch a cold or the flu.

How to take it

When

Take it at about the same time each day, exactly as prescribed.

Food

Works with or without food. Food can help if it upsets your stomach.

Avoid

Don't take antacids with aluminum or magnesium at the same time — space them a couple of hours apart.

Good to know

Tell your doctor if you have any heart rhythm problems before starting — this drug can affect heart rhythm.

Missed a dose?

Take it as soon as you remember. If it's almost time for your next dose, skip the missed one and continue as usual. Never take two doses to make up for one.

Common side effects

Diarrhea or loose stools
Nausea or stomach pain
Headache
Changes in taste

Call a doctor if

Fainting, a racing or fluttering heartbeat, or feeling like your heart is skipping — get help now. This drug can trigger dangerous heart rhythm changes, especially if you already have rhythm problems.
Trouble breathing, swelling of the face or throat, or hives — this can be a serious allergic reaction. Get emergency help now.
Severe watery or bloody diarrhea, during treatment or even weeks after — this can be a serious gut infection (C. diff). Call your doctor; don't just take anti-diarrhea medicine.
Yellowing of the skin or eyes, dark urine, or severe belly pain.

Educational only. This summary is drawn from public FDA labeling and MedlinePlus and simplified for readability. Your prescription label and your pharmacist always come first — doses and instructions vary from person to person.