A creatinine level of 11.3 mg/dL is extremely high and indicates severe, life-threatening kidney failure. This is a medical emergency. You must go to the nearest emergency room or contact a nephrologist (kidney specialist) immediately. At this level, lifestyle changes or standard medications are not enough; you will likely need urgent dialysis to filter dangerous waste products from your blood. Please do not attempt to self-medicate, as many medications can further damage your kidneys. Seek emergency medical care right away.