 [ Symptoms ] how long do symptoms last with antibiotics for strep  i have tested positive for strep and was given a higher does of antibiotics because i was already taken them for a sinus infection my throat is still killing me i am on day 3 of 2000 mg of antibiotics how long should the symptoms last [ Disease ] i used to get strep once or twice a year i received the same treatment just about every time the antibiotics i received usually made me feel better about two to three days after consistent use gone within a week