I am taking cipro (ciprofloxacin) and flagyl for colitis. i have anxiety and take cymbalta and ativan prn. could either antibiotics cause strong fast heartrate?

Not the meds: It's probably the colitis, not the meds. Measure your actual pulse and BP and report these. Let's see how "strong and fast" your heart rate really is.

Tachycardia and drug: Yes. Cipro (ciprofloxacin) and Flagyl both cause tachycardia in some patients, so does Cymbalta. Ativan is associated with both fast heart rate and a slowed heart rate. Talk with you Gastroenterologist.

Unlikely: Cymbalta (duloxetine) and ativan pm ordinarily ease anxiety, You need to ask your prescribing doctor about this