It is effective in treating infections caused by bacteria. Used to treat patients with bacterial infections such as pneumonia , anthrax , syphilis , bronchitis , gastroenteritis and plague. These antibiotics are also used to fight infections of the throat , skin , ears , nose , sinuses , bones , respiratory tract and urinary tract. Side Effects Dizziness or palpitations Heartbeat Headache Chest pain Nausea or vomiting