Moxifloxacin is an antibiotic that belongs to the group of medications known as quinolones. It is used to treat infections caused by certain bacteria.

Moxifloxacin tablets are most commonly used to treat infections of the sinuses and lungs. It may also be used to treat skin and abdominal infections. Moxifloxacin given intravenously (injected into a vein) is most commonly used to treat infections of the lungs and complicated infections of the skin and abdomen.

This medication may be available under multiple brand names and/or in several different forms. Any specific brand name of this medication may not be available in all of the forms or approved for all of the conditions discussed here. As well, some forms of this medication may not be used for all of the conditions discussed here.

Your doctor may have suggested this medication for conditions other than those listed in these drug information articles. If you have not discussed this with your doctor or are not sure why you are taking this medication, speak to your doctor. Do not stop taking this medication without consulting your doctor.

Do not give this medication to anyone else, even if they have the same symptoms as you do. It can be harmful for people to take this medication if their doctor has not prescribed it.

The recommended adult dose of moxifloxacin is 400 mg once daily. The medication may be taken for 5 to 21 days depending on the particular infection being treated.

Moxifloxacin tablets should be swallowed whole with plenty of fluids. They may be taken with or without food. Moxifloxacin tablets should be taken at least 4 hours before or 8 hours after multivitamins that contain iron or zinc, antacids that contain magnesium or aluminum, or sucralfate. Ask your pharmacist if you are not sure if your multivitamins or antacids contain these ingredients.

Many things can affect the dose of medication that a person needs, such as body weight, other medical conditions, and other medications. If your doctor has recommended a dose different from the ones listed here, do not change the way that you are taking the medication without consulting your doctor.

Finish all of the medication, even if you have started to feel better.

It is important to take this medication exactly as prescribed by your doctor.

If you miss a dose, take it as soon as possible and continue with the next dose 24 hours later. Do not take more than 1 dose within any 24 hour period. Do not take a double dose to make up for a missed one. If you are not sure what to do after missing a dose, contact your doctor or pharmacist for advice.

Store the tablets at room temperature, away from heat and direct light, and do not allow them to freeze.

Keep this medication out of the reach of children.

Each dull red, modified-capsule-shaped, film-coated tablet debossed with "E 18" on one side contains 400 mg of moxifloxacin. Nonmedicinal ingredients: cellulose microcrystalline, sodium starch glycolate, povidone, and magnesium stearate; coating: Opadry Pink 03B54025 (hypromellose, titanium dioxide, macrogol, and iron oxide red).

Do not use this medication if you:

• are allergic to moxifloxacin or any ingredients of the medication
• are allergic to other quinolone antibiotics (e.g., ciprofloxacin, norfloxacin)

Many medications can cause side effects. A side effect is an unwanted response to a medication when it is taken in normal doses. Side effects can be mild or severe, temporary or permanent.

The side effects listed below are not experienced by everyone who takes this medication. If you are concerned about side effects, discuss the risks and benefits of this medication with your doctor.

The following side effects have been reported by at least 1% of people taking this medication. Many of these side effects can be managed, and some may go away on their own over time.

Contact your doctor if you experience these side effects and they are severe or bothersome. Your pharmacist may be able to advise you on managing side effects.

• dizziness or lightheadedness
• headache
• inability to think clearly
• nausea
• nightmares
• trouble sleeping

Although most of the side effects listed below don't happen very often, they could lead to serious problems if you do not seek medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

• agitation
• anxiety
• confusion or changes in thought patterns
• hallucinations (seeing, hearing, or feeling things that are not there)
• memory loss
• muscle or joint pain
• muscle weakness
• nervousness
• numbness, tingling, or weakness
• pain, swelling, or rupture of a tendon
• paranoia, loss of touch with reality
• signs of depression (e.g., poor concentration, changes in weight, changes in sleep, decreased interest in activities, thoughts of suicide)
• swelling, redness, or other irritation at the place of injection (for intravenous only)
• symptoms of high blood sugar (e.g., frequent urination, increased thirst, excessive eating, unexplained weight loss, poor wound healing, infections, fruity breath odour)
• symptoms of low blood sugar (e.g., cold sweat, cool pale skin, headache, fast heartbeat, weakness)
• symptoms of liver problems (e.g., abdominal pain, dark urine, yellowing of the skin or eyes, nausea, pale stools)
• tremors
• vision changes

Stop taking the medication and seek immediate medical attention if any of the following occur:

• diarrhea (watery and severe; may also be bloody)
• fainting
• irregular or fast heart rate
• seizures
• signs of a severe allergic reaction (e.g.: hives, difficulty breathing, or swelling of the face, tongue, or throat)
• skin rash, especially if skin is blistering, loosening, or peeling
• thoughts of suicide or self-harm
• sudden, severe abdominal, chest, or back pain

Some people may experience side effects other than those listed. Check with your doctor if you notice any symptom that worries you while you are taking this medication.

Before you begin taking a medication, be sure to inform your doctor of any medical conditions or allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should use this medication.

Bacterial resistance: Misuse of an antibiotic such as moxifloxacin may lead to the growth of resistant bacteria that will not be killed by the antibiotic. If this happens, the antibiotic may not work for you in the future. Although you may begin to feel better when you first start taking moxifloxacin, you need to take all the medication exactly as directed by your doctor to finish ridding your body of the infection and to prevent resistant bacteria from taking hold. Do not take moxifloxacin or other antibiotics to treat a viral infection such as the common cold; antibiotics do not kill viruses, and using them to treat viral infections can lead to the growth of resistant bacteria.

Allergic reactions: In rare cases, some people may develop a severe allergic reaction to this medication. Signs of a severe reaction include a severe rash, swollen face, or difficulty breathing. If these occur, get immediate medical attention.

Antibiotic-related diarrhea: As with other antibiotics, moxifloxacin can cause a severe form of diarrhea associated with the condition called pseudomembranous colitis. If you develop severe diarrhea while taking this medication, contact your doctor as soon as possible.

Behaviour and movement changes: Rarely, this medication can cause movement disorders or behaviour changes such as agitation, anxiety, confusion, depression, tremors, hallucinations, and other mood changes. If you experience any of these, or notice them in a family member who is taking this medication, stop taking this medication and contact your doctor immediately.

Diabetes: Moxifloxacin may cause changes in blood sugar levels (may cause a loss of blood glucose control) and glucose tolerance may change. People with diabetes may find it necessary to monitor their blood sugar more frequently while using this medication.

If you have diabetes or are at risk for developing diabetes, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Driving and operating heavy machinery: Moxifloxacin may cause dizziness and drowsiness, impairing your ability to drive or operate machinery, especially when combined with alcohol. Avoid driving, operating machinery, or performing other potentially hazardous tasks until you have determined how this medication affects you.

Liver problems: Liver disease or reduced liver function may cause this medication to build up in the body, causing side effects. If you have liver problems, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

This medication may cause liver problems that in rare cases can be fatal. If you experience symptoms of liver problems (e.g., yellowing of the skin and eyes, abdominal pain, dark urine, pale stools, loss of appetite, itchy skin) while taking this medication, contact your doctor immediately. People with a severe reduction in liver function should not use this medication.

Neuromuscular disorders: Moxifloxacin, like other antibiotics in this family, can cause increased muscle weakness, including difficulty breathing, for people with myasthenia gravis (an autoimmune disorder that causes muscle weakness). If you have myasthenia gravis, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed. Generally, moxifloxacin is not recommended for people with myasthenia gravis.

Palpitations and fainting spells: See a doctor as soon as possible if you experience palpitations (irregular or rapid heartbeat) or fainting spells while taking moxifloxacin.

Peripheral neuropathy: Although rare, moxifloxacin may affect the nerves of the skin and limbs. If you start to feel pain, burning, tingling, numbness, or weakness, stop taking this medication and contact your doctor immediately.

QT prolongation: This medication can lengthen heartbeat as shown on an electrocardiogram test, also known as QT prolongation. Very rare cases of abnormal heartbeat have been reported by people on moxifloxacin, but these reports generally involved people who had conditions that made it more likely for them to have abnormal heartbeat, or who had been taking other medications that can increase the risk of developing an abnormal heartbeat.

You are more at risk for this type of abnormal heart rhythm and its complications if you:

• are female
• are older than 65 years of age
• have a family history of sudden cardiac death
• have a history of heart disease or abnormal heart rhythms
• have a slow heart rate
• have congenital prolongation of the QT interval
• have diabetes
• have had a stroke
• have low potassium, magnesium, or calcium levels
• have nutritional deficiencies

If you have heart disease and abnormal heart rhythms, or if you are taking certain medications (e.g., verapamil, atazanavir), discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Seizures: Seizures may rarely occur with this medication. If you have a medical condition that increases the risk of seizures, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

If you have a seizure while taking this medication, stop taking the medication and get immediate medical attention.

Sun sensitivity: People who take moxifloxacin may be more likely to experience sunburn. While taking moxifloxacin, avoid excessive sunlight or artificial ultraviolet light exposure (e.g., sun beds, sunlamps). Stop taking the medication and contact your doctor if you develop sun sensitivity.

Tendonitis: Moxifloxacin may increase the chance of tendon injury. Injury occurs more commonly for seniors who are also taking corticosteroid medications. If there is any new pain in the tendons or joints, stop taking moxifloxacin, avoid physical exercise, and consult your doctor.

Pregnancy: This medication should not be used during pregnancy unless the benefits outweigh the risks. If you become pregnant while taking this medication, stop taking it immediately and contact your doctor.

Breast-feeding: It is not known if moxifloxacin passes into breast milk. If you are breast-feeding and taking this medication, it may affect your baby. Talk to your doctor about whether you should continue breast-feeding.

Children: The safety and effectiveness of this medication have not been established for children under 18 years of age.

For a full list of interactions, use the Drug Interaction Checker available on the Drugs.com website.

If you are taking other medications, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:

• stop taking one of the medications,
• change one of the medications to another,
• change how you are taking one or both of the medications, or
• leave everything as is.

An interaction between two medications does not always mean that you must stop taking one of them. Speak to your doctor about how any drug interactions are being managed or should be managed.

Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them.