<s>[INST] I got a bad lung infection in early November, coughing very bad. Everything cleared up with Biaxin XL, except yellow mucus in the morning that turns to clear mucus shortly after awaking. My throat feels sore, especially these past two days. The back of the throat near the roof of my  mouth only is sore now after gargling with slat water last night.I have a bottle of Biaxin Xl on hand that I was to use back in December if my throat swab came back positive. It came back negative but I have been having these sore throats and yellow or green mucus almost since the first treatment of Biaxin XL in November.I wonder, should I take the Biaxin XL 500 MG twice daily now. I find it difficult to get to my doctors office, being handicapped. [/INST] Hi. Welcome to Chat Doctor . I have gone through your query and can understand your concern. As per your complaint persistent sore throat along with yellow mucous can be due to number of causes like chronic upper respiratory tract infection, sinusitis, post nasal Chat Doctor. . I would suggest you to consult an Otolaryngologies or a Pulmonologist and get evaluated and a thorough clinical evaluation and investigations like sputum culture, throat swab culture, chest x-ray and blood tests can help in diagnosis and treatment will depend upon the cause. You can be advised a course of antibiotics, anti-inflammatory painkiller, decongestants, Multics, warm saline gargles, steam inhalations and use a humidifier in your room. Chew vitamin C pellets and suck throat lozenges. Hope this information helps. Thanks and regards. </s>