Last Tuesday my husband visited the doctor after being sick with a fever & unable to go to work for 4 days. He was prescribed Clarithromycin *P 500 MG for an upper respiratory infection. On Thursday, he returned to the Doctor because it did not appear he was improving. He was also experiencing pain in his groin area. After a Chest X-Ray, it was determined he did not have pneumonia, however, they did find blood in his urine and he was diagnosed with a Kidney infection. He was given a prescription for Levofloxacin *P 500 MG. There seems to be some improvement but he still has a low-grade fever (99.9\6-100.3) and cough after 4 days. Looking for any guidance or thoughts. Is this normal? Could it be something more? I know that time is critical having seem how quickly people can succumb to fatal illness. Should we be concerned that after 4 days he still is weak & has a fever?