Moxifloxacin is a fluoroquinolone (flor-o-KWIN-o-lone) antibiotic that fights bacteria in the body.

Moxifloxacin is used to treat different types of bacterial infections of the skin, sinuses, lungs, or stomach.

Fluoroquinolone antibiotics can cause serious or disabling side effects that may not be reversible. Moxifloxacin should be used only for infections that cannot be treated with a safer antibiotic.

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

You should not use this medicine if you are allergic to moxifloxacin or other fluoroquinolones (ciprofloxacin, gemifloxacin, levofloxacin, ofloxacin, norfloxacin, and others).

Moxifloxacin may cause swelling or tearing of a tendon (the fiber that connects bones to muscles in the body), especially in the Achilles' tendon of the heel. This can happen during treatment or up to several months after you stop taking moxifloxacin. Tendon problems may be more likely to occur if you are over 60, if you take steroid medication, or if you have had a kidney, heart, or lung transplant.

Tell your doctor if you have ever had:

• tendon problems, bone problems, arthritis, or other joint problems;
• blood circulation problems, aneurysm, narrowing or hardening of the arteries;
• heart problems, high blood pressure;
• a genetic disease such as Marfan syndrome or Ehler's-Danlos syndrome;
• diabetes;
• a muscle or nerve disorder, such as myasthenia gravis;
• liver or kidney disease;
• a seizure, head injury, or brain tumor;
• long QT syndrome (in you or a family member); or
• low levels of potassium in your blood (hypokalemia).

Moxifloxacin is not approved for use by anyone younger than 18 years old.

Tell your doctor if you are pregnant or breastfeeding.

Use Moxifloxacin (Avelox) exactly as directed on the label, or as prescribed by your doctor. Do not use in larger or smaller amounts or for longer than recommended.

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).

Moxifloxacin can cause serious side effects, including tendon problems, side effects on your nerves (which may cause permanent nerve damage), serious mood or behavior changes (after just one dose), or low blood sugar (which can lead to coma).

Stop using this medicine and call your doctor at once if you have:

• low blood sugar--headache, hunger, sweating, irritability, dizziness, nausea, fast heart rate, or feeling anxious or shaky;
• nerve symptoms in your hands, arms, legs, or feet--numbness, weakness, tingling, burning pain;
• serious mood or behavior changes--nervousness, confusion, agitation, paranoia, hallucinations, memory problems, trouble concentrating, thoughts of suicide; or
• signs of tendon rupture--sudden pain, swelling, bruising, tenderness, stiffness, movement problems, or a snapping or popping sound in any of your joints (rest the joint until you receive medical care or instructions).

In rare cases, moxifloxacin may cause damage to your aorta, the main blood artery of the body. This could lead to dangerous bleeding or death. Get emergency medical help if you have severe and constant pain in your chest, stomach, or back.

Also stop using moxifloxacin and 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);
• muscle weakness, breathing problems;
• a seizure (convulsions);
• any skin rash, no matter how mild;
• increased pressure inside the skull--severe headaches, ringing in your ears, vision problems, pain behind your eyes; or
• liver problems--upper stomach pain, loss of appetite, dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes).

Common side effects may include:

• nausea, diarrhea;
• dizziness; 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.

Avoid driving or hazardous activity until you know how this medicine will affect you. Your reactions could be impaired.

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.

Moxifloxacin 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. Tell your doctor if you have severe burning, redness, itching, rash, or swelling after being in the sun.