What antibiotic is SAFE to take with flecainide. I get chronic bronchitis.

Doxycycline and Amoxicillin are usually the antibiotics prescribed to treat bronchitis.

I am not a Dr., you need to consult with your Dr. in order to get the right one prescribed to you. In the meantime I checked for potential interactions and Doxycycline and Amoxicillin do not interact with Flecainide, but as I mentioned before, a Dr. has to prescribe them for you , do not self medicate.

Doxycycline-Flecainide:
https://www.drugs.com/interactions-check.php?drug_list=1094-0,940-0

Amoxicillin-Flecainide:
https://www.drugs.com/interactions-check.php?drug_list=1094-0,187-0

Interactions between your drugs
Moderate
azithromycin flecainide
Applies to: Zithromax (azithromycin), flecainide

Using azithromycin together with flecainide can increase the risk of an irregular heart rhythm that may be serious and potentially life-threatening, although it is a relatively rare side effect. You may be more susceptible if you have a heart condition called congenital long QT syndrome, other cardiac diseases, conduction abnormalities, or electrolyte disturbances (for example, magnesium or potassium loss due to severe or prolonged diarrhea or vomiting). Talk to your doctor if you have any questions or concerns. You should seek immediate medical attention if you develop sudden dizziness, lightheadedness, fainting, shortness of breath, or heart palpitations during treatment with these medications, whether together or alone. It is important to tell your doctor about all other medications you use, including vitamins and herbs. Do not stop using any medications without first talking to your doctor.

https://www.drugs.com/interactions-check.php?drug_list=1094-0,300-144