Azithromycin is an antibiotic that fights bacteria.

Azithromycin is used to treat many different types of infections caused by bacteria, such as respiratory infections, skin infections, ear infections, eye infections, and sexually transmitted diseases.

Azithromycin may also be used for purposes not listed in this medication guide.

You should not use azithromycin if you have ever had jaundice or liver problems when you have previously taken this medicine.

Azithromycin comes as a tablet, an extended-release (long-acting) suspension (liquid), and a suspension (liquid) to take by mouth. The tablets and suspension (Zithromax) are usually taken with or without food once a day for 1-5 days. When used for the prevention of disseminated MAC infection, azithromycin tablets are usually taken with or without food once weekly. The extended-release suspension (Zmax) is usually taken on an empty stomach (at least 1 hour before or 2 hours after a meal) as a one-time dose. To help you remember to take azithromycin, take it around the same time every day. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take azithromycin exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.

Shake the liquid well before each use to mix the medication evenly. Use a dosing spoon, oral syringe, or measuring cup to measure the correct amount of medication. Rinse the measuring device with water after taking the full dose of medication.

If you receive azithromycin powder for suspension (Zithromax) in the single-dose, 1-gram packet, you must first mix it with water before you take the medication. Mix the contents of the 1-gram packet with 1/4 cup (60 mL) of water in a glass and consume the entire contents immediately. Add an additional 1/4 cup (60 mL) of water to the same glass, mix, and consume the entire contents to ensure that you receive the entire dose.

If you receive azithromycin extended-release suspension (Zmax) as a dry powder, you must first add water to the bottle before you take the medication. Open the bottle by pressing down on the cap and twisting. Measure 1/4 cup (60 mL) of water, and add to the bottle. Close the bottle tightly, and shake well to mix. Use the azithromycin extended-release suspension within 12 hours of receiving it from the pharmacy or after adding water to the powder.

If you vomit within an hour after taking azithromycin, call your doctor right away. Your doctor will tell you if you need to take another dose. Do not take another dose unless your doctor tells you to do so.

You should begin to feel better during the first few days of treatment with azithromycin. If your symptoms do not improve, or get worse, call your doctor.

Take azithromycin until you finish the prescription, even if you feel better. Do not stop taking azithromycin unless you experience the severe side effects described in the SIDE EFFECTS section. If you stop taking azithromycin too soon or skip doses, your infection may not be completely treated and the bacteria may become resistant to antibiotics.

Ask your pharmacist or doctor for a copy of the manufacturer's information for the patient.

Take azithromycin exactly as prescribed by your doctor. Follow all directions on your prescription label. Do not take this medicine in larger or smaller amounts or for longer than recommended. The dose and length of treatment may not be the same for every type of infection.

You may take most forms of azithromycin with or without food.

Take Zmax extended release liquid (oral suspension) on an empty stomach, at least 1 hour before or 2 hours after a meal.

To use the oral suspension single dose packet: Open the packet and pour the medicine into 2 ounces of water. Stir this mixture and drink all of it right away. Do not save for later use. To make sure you get the entire dose, add 2 more ounces of water to the same glass, swirl gently and drink right away.

Throw away any mixed Zmax oral suspension (extended release formulation) that has not been used within 12 hours. Throw away any immediate-release suspension that has not been used within 10 days.

Shake the oral suspension (liquid) well just before you measure a dose. Measure liquid medicine with the dosing syringe provided, or with a special dose-measuring spoon or medicine cup. If you do not have a dose-measuring device, ask your pharmacist for one.

Use this medicine for the full prescribed length of time. Your symptoms may improve before the infection is completely cleared. Skipping doses may also increase your risk of further infection that is resistant to antibiotics. Azithromycin will not treat a viral infection such as the flu or a common cold.

Store at room temperature away from moisture and heat.

You should not use azithromycin if you are allergic to it, or if:

• you have ever had jaundice or liver problems caused by taking azithromycin; or

• you are allergic to similar drugs such as clarithromycin, erythromycin, or telithromycin.

To make sure azithromycin is safe for you, tell your doctor if you have ever had:

• liver disease;

• kidney disease;

• myasthenia gravis;

• a heart rhythm disorder;

• low levels of potassium in your blood; or

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

This medicine is not expected to harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant.

It is not known whether azithromycin passes into breast milk or if it could harm a nursing baby. Tell your doctor if you are breast-feeding a baby.

Take the missed dose as soon as you remember. Skip the missed dose if it is almost time for your next scheduled dose. Do not take extra medicine to make up the missed dose.

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

Keep this medication in the container it came in, tightly closed, and out of reach of children. Store azithromycin tablets, suspension, and extended-release suspension at room temperature and away from excess heat and moisture (not in the bathroom). Do not refrigerate or freeze the extended-release suspension. Discard any azithromycin suspension that is left over after 10 days or no longer needed. Discard any unused extended-release azithromycin suspension after dosing is complete or 12 hours after preparation.

Unneeded medications should be disposed of in special ways to ensure that pets, children, and other people cannot consume them. However, you should not flush this medication down the toilet. Instead, the best way to dispose of your medication is through a medicine take-back program. Talk to your pharmacist or contact your local garbage/recycling department to learn about take-back programs in your community. See the FDA's Safe Disposal of Medicines website (http://goo.gl/c4Rm4p) for more information if you do not have access to a take-back program.

It is important to keep all medication out of sight and reach of children as many containers (such as weekly pill minders and those for eye drops, creams, patches, and inhalers) are not child-resistant and young children can open them easily. To protect young children from poisoning, always lock safety caps and immediately place the medication in a safe location – one that is up and away and out of their sight and reach. http://www.upandaway.org

Unless your doctor tells you otherwise, continue your normal diet.

Do not take antacids that contain aluminum or magnesium within 2 hours before or after you take azithromycin. This includes Acid Gone, Aldroxicon, Alternagel, Di-Gel, Gaviscon, Gelusil, Genaton, Maalox, Maldroxal, Milk of Magnesia, Mintox, Mylagen, Mylanta, Pepcid Complete, Rolaids, Rulox, and others. These antacids can make azithromycin less effective when taken at the same time.

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. Do not use anti-diarrhea medicine unless your doctor tells you to.

Avoid exposure to sunlight or tanning beds. Azithromycin can make you sunburn more easily. Wear protective clothing and use sunscreen (SPF 30 or higher) when you are outdoors.

Avoid other drugs that can cause QT prolongation or irregular heart rhythm.

Get emergency medical help if you have signs of an allergic reaction to azithromycin: (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, flu-like symptoms, muscle aches, severe weakness, unusual bruising, or yellowing of your skin or eyes. This reaction may occur several weeks after you began using azithromycin.

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, upper stomach pain, itching, tired feeling, loss of appetite, dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes).

Call your doctor right away if a baby taking azithromycin 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 azithromycin side effects may include:

• diarrhea;

• nausea, vomiting, stomach pain; or

• headache.

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 current medicines and any you start or stop using, especially:

• digoxin; or

• clarithromycin; or

• a blood thinner - warfarin, Coumadin, Jantoven.

This list is not complete. Other drugs may interact with azithromycin, including prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible interactions are listed in this medication guide.

Keep all appointments with your doctor and the laboratory. Your doctor may order certain lab tests to check your body's response to azithromycin.

Do not let anyone else take your medication. Your prescription is probably not refillable. If you still have symptoms of infection after you finish the azithromycin, call your doctor.

It is important for you to keep a written list of all of the prescription and nonprescription (over-the-counter) medicines you are taking, as well as any products such as vitamins, minerals, or other dietary supplements. You should bring this list with you each time you visit a doctor or if you are admitted to a hospital. It is also important information to carry with you in case of emergencies.

You should start to feel better within a few days of taking azithromycin, but this will depend on the type of infection you have.

Let your doctor know if you don’t improve or feel worse after using this medicine.

Finish the whole course of azithromycin. Don’t stop taking this medicine, even if your symptoms subside.

Your dosage will depend on your medical condition, your age, the formulation of azithromycin you use, and other factors.

A typical dosage of immediate-release azithromycin for adults might be 500 milligrams (mg) a day on day one, followed by 250 mg a day on days two to five.

If your doctor prescribes the extended-release form of azithromycin, you may take 2 grams (g) once as a single dose.

Azithromycin is used to treat a variety of infections. Your doctor may recommend it for conditions that aren’t listed in this medical guide.