Hello. What are the safest antibiotics for use by seniors with congestive heart failure taking blood thinner medication? As an example, if a patient had a bladder infection, which antibiotics are least likely to have an adverse reaction with blood pressu

Bactrim (sulfamethoxazole and trimethoprim) For your situation, Bactrim (sulfamethoxazole and trimethoprim) is likely the best choice. However I will defer to our urologist colleagues.
If. If the blood thinner you meant was warfarin, then Nitrofurantoin has less drug interaction with warfarin. Dosage should be adjusted to kidney function. It is considered safe for patients with congestive heart failure.