See also How to Use section.
Your doctor or pharmacist may already be aware of any possible drug interactions
and may be monitoring you for them. Do not start, stop, or change the dosage
of any medicine before checking with them first.
This drug should not be used with the following medications because very serious
interactions may occur: strontium, certain drugs that affect the heart rhythm
(antiarrhythmics that may cause QT prolongation such as amiodarone, dofetilide,
quinidine, procainamide, sotalol).
If you are currently using any of these medications listed above, tell your
doctor or pharmacist before starting levofloxacin.
Other drugs besides levofloxacin and those listed above that may affect the
heart rhythm (QT prolongation in the EKG) include certain macrolide antibiotics
(e.g., erythromycin, clarithromycin), and certain antipsychotic medications
(e.g., pimozide, thioridazine, ziprasidone), among others. QT prolongation can
infrequently result in serious (rarely fatal) fast/irregular heartbeat and other
symptoms (e.g., severe dizziness, fainting) that require immediate medical treatment.
Ask your doctor or pharmacist for more details and for instructions on how you
may reduce the risk of this effect.
Before using this medication, tell your doctor or pharmacist of all prescription
and nonprescription/herbal products you may use, especially of: "blood
thinners" (e.g., warfarin), corticosteroids (e.g., dexamethasone, prednisone),
drugs to treat diabetes (e.g., glyburide, insulin), live bacterial vaccines
(e.g., typhoid, BCG), nonsteroidal anti-inflammatory drugs (NSAIDs such as ibuprofen,
naproxen), urinary alkalinizers (e.g., potassium/sodium citrate), certain "water
pills" (potassium-wasting diuretics such as furosemide, hydrochlorothiazide).
Also report the use of drugs that might increase seizure risk when combined
with this medication such as isoniazid (INH), phenothiazines (e.g., thioridazine),
theophylline, or tricyclic antidepressants (e.g., amitriptyline). Consult your
doctor or pharmacist for details.
This medication may interfere with certain laboratory tests (e.g., urine screening
for opiates), possibly causing false test results. Make sure laboratory personnel
and all your doctors know you use this drug.
This document does not contain all possible interactions. Therefore, before
using this product, tell your doctor or pharmacist of all the products you use.
Keep a list of all your medications with you, and share the list with your doctor
and pharmacist.