Oritaxim 500 mg. Injections are antibiotic medications used to treat bacterial infections in the body. Oritaxim 500 mg. Injection is a medication that eliminates infection-causing microorganisms in your body. It is frequently injected by a doctor or nurse into a vein or muscle. This medication is used to treat a wide range of infections, including those affecting the brain (meningitis), lungs (pneumonia), ear, abdomen, urinary tract, bones and joints, skin, blood, and heart. This medication normally helps you feel better within a few days. To maximize your benefits, strictly follow your doctor's directions.