Before taking this medication, it is best to advise your doctor if you are allergic to Levofloxacin; or to other quinolone antibiotics (such as ciprofloxacin, moxifloxacin, ofloxacin); or to any other medications or allergies in general.
Also it is best to notify your doctor of your medical history. Inform you doctor if you have had any of the following; diabetes, joint/tendon problems (such as tendonitis, bursitis), kidney problems, mental/mood disorders (such as depression), a certain muscle condition (myasthenia gravis), nerve problems (such as peripheral neuropathy), seizure disorder, blood vessel problems (such as aneurysm or blockage of the aorta or other blood vessels, hardening of the arteries), high blood pressure, certain genetic conditions (Marfan syndrome, Ehlers-Danlos syndrome).
Levofloxacin may cause a condition that affects the heart rhythm (QT prolongation). QT prolongation can rarely cause serious (rarely fatal) fast/irregular heartbeat and other symptoms (such as severe dizziness, fainting) that need medical attention right away.
The risk of QT prolongation may be increased if you have certain medical conditions or are taking other drugs that may cause QT prolongation. Before using levofloxacin, tell your doctor or pharmacist of all the drugs you take and if you have any of the following conditions: certain heart problems (heart failure, slow heartbeat, QT prolongation in the EKG), family history of certain heart problems (QT prolongation in the EKG, sudden cardiac death).
Low levels of potassium or magnesium in the blood may also increase your risk of QT prolongation. This risk may increase if you use certain drugs (such as diuretics/"water pills") or if you have conditions such as severe sweating, diarrhea, or vomiting. Talk to your doctor about using levofloxacin safely.
Levofloxacin may rarely cause serious changes in blood sugar, especially if you have diabetes. Check your blood sugar regularly as directed and share the results with your doctor. Watch for symptoms of high blood sugar such as increased thirst/urination. Also watch for symptoms of low blood sugar such as sudden sweating, shaking, fast heartbeat, hunger, blurred vision, dizziness, or tingling hands/feet. It is a good habit to carry glucose tablets or gel to treat low blood sugar. If you don't have these reliable forms of glucose, rapidly raise your blood sugar by eating a quick source of sugar such as table sugar, honey, or candy, or by drinking fruit juice or non-diet soda. Tell your doctor right away about the reaction and the use of this product. To help prevent low blood sugar, eat meals on a regular schedule, and no not skip meals. Your doctor may need to switch you to another antibiotic or adjust your diabetes medications if any reaction occurs.