Zithromax Z-Pak is used to treat many different types of infections caused by bacteria, including infections of the lungs, sinus, throat, tonsils, skin, urinary tract, cervix, or genitals.

Zithromax Z-Pak may also be used for purposes not listed in this medication guide.

You should not use Zithromax Z-Pak if you have ever had an allergic reaction, jaundice, or liver problems while taking Zithromax Z-Pak. You should not use this medicine if you have ever had a severe allergic reaction to similar drugs such as clarithromycin, erythromycin, or telithromycin.

Follow all directions on your prescription label and read all medication guides or instruction sheets. Use the medicine exactly as directed.

Zithromax Z-Pak oral is taken by mouth. This medicine injection is given as an infusion into a vein, usually for 2 days before you switch to this medicine oral. A healthcare provider will give you this injection.

You may take Zithromax Z-Pak oral with or without food.

Shake the oral suspension (liquid) before you measure a dose. Use the dosing syringe provided, or use a medicine dose-measuring device (not a kitchen spoon).

Use Zithromax Z-Pak for the full prescribed length of time, even if your symptoms quickly improve. Skipping doses can increase your risk of infection that is resistant to medication. Zithromax Z-Pak will not treat a viral infection such as the flu or a common cold.

Store at room temperature away from moisture and heat. Throw away any unused liquid medicine after 10 days.

You should not use Zithromax Z-Pak if you are allergic to it, or if you have ever had:

• jaundice or liver problems caused by taking Zithromax Z-Pak; or

• a severe allergic reaction to similar drugs such as clarithromycin, erythromycin, or telithromycin.

Zithromax Z-Pak oral should not be used to treat pneumonia in people who have:

• cystic fibrosis;

• an infection after being in a hospital;

• an infection in the blood;

• a weak immune system (caused by diseases such as HIV/AIDS or cancer); or

• in older adults and those who are ill or debilitated.

Tell your doctor if you have ever had:

• pneumonia;

• liver or kidney disease;

• myasthenia gravis;

• low levels of potassium in your blood;

• a heart rhythm disorder; or

• long QT syndrome (in you or a family member).

It is not known whether this medicine is effective in treating genital ulcers in women.

Tell your doctor if you are pregnant or breastfeeding. Taking Zithromax Z-Pak while breastfeeding may cause diarrhea, vomiting, or rash in the nursing baby.

Zithromax Z-Pak is not approved for use by anyone younger than 6 months old. This medicine should not be used to treat a throat or tonsil infection in a child younger than 2 years old.

Take the medicine as soon as you can, but skip the missed dose if it is almost time for your next dose. Do not take two doses at one time.

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

Antibiotic medicines can cause diarrhea, which may be a sign of a new infection. If you have diarrhea that is watery or bloody, call your doctor before using anti-diarrhea medicine.

Zithromax Z-Pak could make you sunburn more easily. Avoid sunlight or tanning beds. Wear protective clothing and use sunscreen (SPF 30 or higher) when you are outdoors.

Get emergency medical help if you have signs of an allergic reaction (hives, difficult breathing, swelling in your face or throat) or a severe skin reaction (fever, sore throat, burning in your eyes, skin pain, red or purple skin rash that spreads and causes blistering and peeling).

Seek medical treatment if you have a serious drug reaction that can affect many parts of your body. Symptoms may include: skin rash, fever, swollen glands, muscle aches, severe weakness, unusual bruising, or yellowing of your skin or eyes.

Zithromax Z-Pak may cause serious side effects. Call your doctor at once if you have:

• severe stomach pain, diarrhea that is watery or bloody;

• fast or pounding heartbeats, fluttering in your chest, shortness of breath, and sudden dizziness (like you might pass out); or

• liver problems--nausea, vomiting, loss of appetite, stomach pain (upper right side), tiredness, itching, dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes);

Call your doctor right away if a baby taking Zithromax Z-Pak becomes irritable or vomits while eating or nursing.

Older adults may be more likely to have side effects on heart rhythm, including a life-threatening fast heart rate.

Common side effects of Zithromax Z-Pak may include:

• nausea, vomiting; or

• stomach pain.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Tell your doctor about all your other medicines, especially:

• colchicine;

• digoxin;

• nelfinavir;

• phenytoin;

• an antacid that contains aluminum or magnesium--Acid Gone, Gaviscon, Gelusil, Maalox, Milk of Magnesia, Mylanta, Pepcid Complete, Rolaids, Rulox, and others; or

• a blood thinner--warfarin, Coumadin, Jantoven.

This list is not complete. Other drugs may affect Zithromax Z-Pak, including prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible drug interactions are listed here.