Fluoroquinolones are a class of broad-spectrum antibiotics Overview of Antibiotics Antibiotics are drugs used to treat bacterial infections. They are ineffective against viral infections and most other infections. Antibiotics either kill microorganisms or stop them from reproducing... read more that are used to treat a variety of infections.
Fluoroquinolones include the following:
Fluoroquinolones can be taken by mouth, and some can be given intravenously or as eye drops.
Fluoroquinolones work by interfering with DNA inside bacteria, resulting in death of the bacteria.
Doctors avoid using fluoroquinolones in people who are more likely to develop a serious abnormal heart rhythm Overview of Abnormal Heart Rhythms Abnormal heart rhythms (arrhythmias) are sequences of heartbeats that are irregular, too fast, too slow, or conducted via an abnormal electrical pathway through the heart. Heart disorders are... read more 
(such as people who have a long QT interval Long QT Syndrome and Torsades de Pointes Ventricular Tachycardia Torsades de pointes ventricular tachycardia is a specific type of ventricular tachycardia that occurs in people who have a particular disorder of the heart's electrical activity called long... read more or a very slow heart rate, who take drugs that cause a long QT interval or a very slow heart rate, or who have a low blood level of potassium Hypokalemia (Low Level of Potassium in the Blood) In hypokalemia, the level of potassium in blood is too low. A low potassium level has many causes but usually results from vomiting, diarrhea, adrenal gland disorders, or use of diuretics. A... read more or a low blood level of magnesium Hypomagnesemia (Low Level of Magnesium in the Blood) In hypomagnesemia, the level of magnesium in blood is too low. (See also Overview of Electrolytes and Overview of Magnesium's Role in the Body.) Magnesium is one of the body's electrolytes,... read more ).
(See also Overview of Antibiotics Overview of Antibiotics Antibiotics are drugs used to treat bacterial infections. They are ineffective against viral infections and most other infections. Antibiotics either kill microorganisms or stop them from reproducing... read more .)
Use of Fluoroquinolones During Pregnancy and Breastfeeding
Use of fluoroquinolones during pregnancy is not recommended, but sometimes the benefits of treatment may outweigh the risks. (See also Drug Use During Pregnancy Drug Use During Pregnancy More than 50% of pregnant women take prescription or nonprescription (over-the-counter) drugs or use social drugs (such as tobacco and alcohol) or illicit drugs at some time during pregnancy... read more .)
Use of fluoroquinolones during breastfeeding is not recommended. (See also Drug Use During Breastfeeding Drug Use During Breastfeeding When mothers who are breastfeeding have to take a drug, they wonder whether they should stop breastfeeding. The answer depends on the following: How much of the drug passes into the milk Whether... read more .)
