Levofloxacin
Levofloxacin is a fluoroquinolone antibiotic. It blocks the bacterial enzymes that unwind and reseal DNA during replication, so susceptible bacteria cannot divide. It is prescribed for bacterial infections; it has no effect on viral illness.
It can be taken with or without food, but is kept apart in time from dairy, antacids and mineral supplements, since calcium, iron and magnesium bind the drug in the gut and blunt absorption — the same binding means these minerals are less available while the course runs, and probiotics are spaced apart so the antibiotic does not simply kill them. Skin becomes more sensitive to strong sun during treatment. It can raise the effect of warfarin, and it can shift blood glucose in either direction, which is why creatinine, ALT and glucose may be checked, and why it is worth mentioning metformin and any warfarin use to the prescriber. The full course is finished as prescribed, even once symptoms settle, because stopping early selects for resistant bacteria.
New pain, swelling or a snapping sensation in a tendon, especially the heel, means stop guessing and see a doctor, as tendon damage is a rare but real effect. Fainting, palpitations or an irregular heartbeat (the drug can prolong the QT interval), unusual bruising or bleeding, yellowing skin, or symptoms of very low or very high blood sugar also warrant medical review.
Reference information, not medical advice. Discuss any change with your doctor.