DEAR DR. ROACH: I am a fit 85-year-old woman. I walk regularly and eat healthily. I have severe COPD and have been on the recommended dosage of Symbicort for 40 to 50 years. Within the past several years I have been getting urinary tract infections every second month, if not every month. My doctor has given me a standing order for urinalysis and culture to determine the infection, and prescriptions for an antibiotic to start when needed until the proper source is found. I am concerned that I take antibiotics eight to 10 times per year, sometimes for several weeks. Is there any substitute for Symbicort if that is contributing to these infections? I fear becoming immune to antibiotics. — L.F.