Megamentin 250 mg/125 mg Tablet is a penicillin-type of antibiotic that helps your body fight infections caused by bacteria. It is used to treat infections of the lungs (e.g. pneumonia), ear, nasal sinus, urinary tract, skin, and soft tissue. It will not work for viral infections such as the common cold. Megamentin 250 mg/125 mg Tablet is best taken with a meal to reduce the chance of a stomach upset. You should take it regularly at evenly spaced intervals as per the schedule prescribed by your doctor. Taking it at the same time every day will help you to remember to take it. The dose will depend on what you are being treated for, but you should always complete a full course of this antibiotic as prescribed by your doctor. Do not stop taking it until you have finished, even when you feel better. If you stop taking it early, some bacteria may survive and the infection may come back or worsen.