 [ Symptoms ] compltd 2 wks of antibotics and medrol pack still have sever pain in lung area plerasie how long does plerasie last [ Disease ] it is entirely possible to have multiple infections at the same time but your doctor is right antibiotics should clear any bacterial infections right up the sore throat is likely being caused by post nasal drip from your sinus infection if it is strep you should see small white patches on your tonsils and it is extremely painful if after you finish your round of antibiotics you still have a serious sore throat then you should go back to the doctor for more tests good luck