Avelox (Moxifloxacin)

How does it work?

Avelox tablets contain the active ingredient moxifloxacin hydrochloride, which is a type of medicine known as a quinolone antibiotic. Antibiotics are used to treat infections caused by bacteria.

Moxifloxacin works by killing the bacteria that are causing an infection. It does this by entering the bacterial cells and inhibiting a bacterial enzyme called DNA-gyrase. This enzyme is involved in replicating and repairing the genetic material (DNA) of the bacteria. If this enzyme doesn't work, the bacteria cannot reproduce or repair themselves and this kills the bacteria.

Moxifloxacin kills a variety of different types of bacteria that cause airway infections such as bronchitis, pneumonia and sinusitis. It also kills chlamydia and other bacteria that cause pelvic inflammatory disease in women.

To make sure the bacteria causing an infection are susceptible to moxifloxacin your doctor will take a tissue sample, for example a sputum or blood sample.

What is it used for?

Avelox tablets are used to treat the following infections, when other antibiotics have failed to treat the infection, or in people who cannot be treated with other antibiotics:

  • Acute flare-ups of chronic bronchitis.
  • Pneumonia (except severe cases, or pneumonia which starts during a stay in hospital).
  • Acute bacterial infection of the sinuses (bacterial sinusitis).
  • Mild to moderate pelvic inflammatory disease (PID), when there are no abscesses associated with the infection. Avelox should normally be used in combination with another type of antibiotic for this condition, because one of the types of bacteria that can cause PID (Neisseria gonorrhoeae) is becoming increasingly resistant to moxifloxacin.
  • Avelox tablets may also be used to complete a course of treatment for complicated skin and skin structure infections or community-aqcuired pneumonia, when these infections have been responding to Avelox infusion.

How do I take it?

  • One tablet is taken once a day. The tablets should be swallowed whole with liquid. They may be taken either with or without food.
  • Do not take indigestion remedies, or medicines containing iron or zinc, in the six hours before or after you take this medicine.
  • Unless your doctor tells you otherwise, it is important that you finish the prescribed course of this antibiotic medicine, even if you feel better or it seems the infection has cleared up. Stopping the course early increases the chance that the infection will come back and that the bacteria will grow resistant to the antibiotic.


  • This medicine may cause dizziness and various other side effects that may affect your ability to drive or operate machinery safely. Do not drive or operate machinery until you know how this medicine affects you and you are sure it won't affect your performance.
  • You should make sure you drink plenty of fluid while taking this medicine to avoid getting dehydrated.
  • Avoid exposing your skin to excessive sunlight, sunlamps or sunbeds while taking moxifloxacin, as it may increase the sensitivity of your skin to UV light. If you get a rash or other skin reaction on exposure to sunlight you should stop taking this medicine and consult your doctor.
  • If your eyesight or eyes seem to be affected by this medicine, you should consult your doctor or an eye specialist immediately.
  • Consult your doctor immediately if you experience palpitations or an irregular heartbeat while taking this medicine. Your doctor may want to carry out tests to monitor your heart function.
  • Broad-spectrum antibiotics can sometimes cause inflammation of the bowel (colitis). For this reason, you get diarrhoea either during or after taking this medicine, particularly if it becomes severe or persistent, or contains blood or mucus, you should consult your doctor immediately.
  • This medicine can sometimes cause problems with your nerves. You should tell your doctor straight away if you experience sensations such as pain, burning, tingling, numbness, or weakness while taking this medicine.
  • Quinolone antibiotics may rarely cause tendon inflammation (tendinitis) and tendon rupture. People aged over 60, people who have had a kidney, heart, or lung transplant and those taking corticosteroid medication are most at risk of this. You should stop taking this medicine immediately if you experience any pain or inflammation in your joints during treatment. Rest the affected limb(s) and consult a doctor immediately.
  • This medicine can sometimes cause liver problems that may very rarely become life-threatening. For this reason you should tell your doctor if you experience any of the following symptoms while taking this medicine, as they may suggest a problem with your liver: rapidly feeling weak or unwell, unexplained itching, loss of appetite, nausea and vomiting, abdominal pain, yellowing of the skin or whites of the eyes (jaundice), unusually dark urine or bleeding.
  • This medicine may very rarely cause serious or life-threatening skin reactions. For this reason you should consult your doctor immediately if you get a rash, skin peeling, or painful blisters in the mouth/nose or genitals while taking this medicine.

Use with caution in

  • People over 60 years of age.
  • People using corticosteroid medicines.
  • People who have had a kidney, heart, or lung transplant.
  • People with conditions that increase the risk of abnormal heart rhythms (arrhythmias), for example decreased oxygen supply to the heart, as seen in angina.
  • History of epilepsy.
  • People with an increased tendency to have seizures (fits), for example due to a head injury or withdrawal from alcohol.
  • Lack of the enzyme G6PD in the blood (G6PD deficiency), or a family history of this condition.
  • Abnormal muscle weakness (myasthenia gravis).
  • People with a history of psychiatric illness.

Not to be used in

  • Children and adolescents under 18 years of age.
  • Allergy to other quinolone-type antibiotics, eg ciprofloxacin.
  • History of tendon disorders related to previous use of a quinolone-type antibiotic.
  • Abnormal heart rhythm seen on a heart monitoring trace (ECG) as a 'prolonged QT interval'.
  • People taking other medicines that can cause a 'prolonged QT interval' (see end of factsheet for examples).
  • History of irregular heart beats that caused symptoms (symptomatic arrhythmias).
  • Heart failure.
  • Slow heart rate (bradycardia).
  • People with disturbances in the levels of electrolytes in their blood, particularly low blood potassium levels (hypokalaemia).
  • Decreased liver function.
  • Pregnancy.
  • Breastfeeding.
  • Rare hereditary problems of galactose intolerance, the Lapp lactase deficiency or glucose-galactose malabsorption (Avelox tablets contain lactose).

This medicine should not be used if you are allergic to one or any of its ingredients. Please inform your doctor or pharmacist if you have previously experienced such an allergy.If you feel you have experienced an allergic reaction, stop using this medicine and inform your doctor or pharmacist immediately.

Pregnancy and breastfeeding

Certain medicines should not be used during pregnancy or breastfeeding. However, other medicines may be safely used in pregnancy or breastfeeding providing the benefits to the mother outweigh the risks to the unborn baby. Always inform your doctor if you are pregnant or planning a pregnancy, before using any medicine.

  • This medicine should not be used during pregnancy as it may potentially be harmful to a developing baby. Seek medical advice from your doctor.
  • This medicine may pass into breast milk. It should not be used by breastfeeding mothers because it may be harmful to a nursing infant. Seek medical advice from your doctor.

Label warnings

  • Do not take iron preparations or indigestion remedies at the same time of day as this medication.
  • Take at regular intervals. Complete the prescribed course unless otherwise directed.

Side effects

Medicines and their possible side effects can affect individual people in different ways. The following are some of the side effects that are known to be associated with this medicine. Just because a side effect is stated here does not mean that all people using this medicine will experience that or any side effect. See also the warnings listed above.

Common (affect between 1 in 10 and 1 in 100 people)

  • Nausea, vomiting, abdominal pain or diarrhoea.
  • Oral or vaginal thrush (candidiasis).
  • Headache.
  • Dizziness.

Uncommon (affect between 1 in 100 and 1 in 1000 people)

  • Indigestion, wind or constipation.
  • Loss of appetite.
  • Feeling weak or fatigued (asthenia).
  • Dehydration.
  • Skin reactions such as rash or itching.
  • Pain in the muscles or joints.
  • Disturbances in the normal numbers of blood cells in the blood.
  • Anxiety, hyperactivity or agitation.
  • Tingling or numb sensations.
  • Alteration in taste.
  • Confusion.
  • Difficulty sleeping (insomnia).
  • Sleepiness (somnolence).
  • Tremor.
  • Spinning sensation (vertigo).
  • Visual disturbances, including double or blurred vision.
  • Shortness of breath.
  • Increased heart rate or palpitations.
  • Abnormal heart beats (arrhythmias).
  • Chest pain (angina).
  • Problems with liver function.

Rare (affect between 1 in 1000 and 1 in 10,000 people)

  • Tendon inflammation (tendinitis) - see warning section above.
  • Inflammation of the liver (hepatitis) or jaundice - see warning section above.
  • Kidney failure.
  • Seizures (convulsions).
  • Fainting.
  • Problems with attention, speech or coordination.
  • Abnormal dreams.
  • Hallucinations.
  • Mood swings or depression (tell your doctor straight away if you feel depressed or have any thoughts about harming yourself while you are taking this medicine).
  • Memory loss.
  • Hearing problems.
  • Raised blood sugar levels (hyperglycaemia).
  • Changes in blood pressure.

Very rare (affect less than 1 in 10,000 people)

  • Severe allergic skin reactions - see warning section above.
  • Tendon rupture.
  • Liver failure.
  • Serious abnormal heart rhythms or heart attack.

The side effects listed above may not include all of the side effects reported by the medicine's manufacturer. For more information about any other possible risks associated with this medicine, please read the information provided with the medicine or consult your doctor or pharmacist.

How can this medicine affect other medicines?

It is important to tell your doctor or pharmacist what medicines you are already taking, including those bought without a prescription and herbal medicines, before you start treatment with this medicine. Similarly, check with your doctor or pharmacist before taking any new medicines while taking this one, to make sure that the combination is safe.

This medicine must not be taken with other medicines that can increase the risk of abnormal heart rhythms ('prolonged QT interval' on a heart monitoring trace or ECG), for example those listed below:

  • atomoxetine
  • medicines to treat abnormal heart rhythms (antiarrhythmics), eg amiodarone, procainamide, quinidine, disopyramide, sotalol
  • the antihistamines astemizole, terfenadine or mizolastine
  • certain antidepressants, eg maprotiline, amitriptyline, imipramine
  • certain antipsychotics, eg thioridazine, chlorpromazine, sertindole, haloperidol, pimozide
  • certain antimalarials, eg halofantrine, chloroquine, quinine, Riamet, mefloquine
  • certain antimicrobials, eg erythromycin by injection, voriconazole or pentamidine
  • cisapride.

This medicine should be used with caution in people who are taking medicines that can reduce the amount of potassium in the blood, because if blood potassium falls too low this may increase the risk of abnormal heart rhythms. Medicines that can lower blood potassium include the following:

  • corticosteroids, eg beclometasone, prednisolone
  • diuretics, eg bendroflumethiazide, furosemide
  • beta agonist bronchodilators, eg salbutamol.

You should not take any of the following medicines at the same time of day as your moxifloxacin dose, as they can reduce the absorption of the moxifloxacin from the gut and make it less effective. If you need to take any of these, the doses should be separated from your moxifloxacin dose by at least six hours:

  • antacids containing magnesium or aluminium
  • preparations containing iron or zinc
  • sucralfate
  • Videx (didanosine) chewable/dispersible tablets (these contain an antacid).

Strontium ranelate may also reduce the absorption of moxifloxacin from the gut and could make it less effective. If you are taking strontium for osteoporosis its manufacturer recommends that you stop taking it temporarily while you are taking a course of moxifloxacin.

Charcoal tablets (sometimes used for wind or indigestion) should not be taken while you are taking this antibiotic, because they can prevent it being absorbed into the bloodstream.

The manufacturer of this medicine recommends that people who are taking anticoagulant medicines to prevent blood clots, eg warfarin, should have their blood clotting time (INR) monitored more frequently while taking this antibiotic.

Oral typhoid vaccine (Vivotif) should not be taken until at least three days after you have finished a course of this antibiotic, because the antibiotic could make the vaccine less effective.

In the past, women using hormonal contraception such as the pill or patch would be advised to use an extra method of contraception (eg condoms) while having treatment with an antibiotic like this one and for seven days after finishing the course. However, this advice has now changed. You no longer need to use an extra method of contraception with the pill, patch or vaginal ring while you have a course of antibiotics. This change in advice comes because to date there is no evidence to prove that antibiotics (other than rifampicin or rifabutin) affect these contraceptives. This is the latest guidance from the Faculty of Sexual & Reproductive Healthcare.

However, if you are taking the contraceptive pill and experience vomiting or diarrhoea as a result of treatment with this antibiotic, you should follow the instructions for vomiting and diarrhoea described in the leaflet provided with your pills.

Other medicines containing the same active ingredient

There are currently no other medicines available in the UK that contain moxifloxacin as the active ingredient.