Drug-induced bradycardia.

A 45-year-old woman presented to the hospital with bloody diarrhoea and significant weight loss over the past 1 month. On admission and evaluation, she was found to have acute ulcerative colitis. She was started on prednisolone and mesalamine therapy. Within 24 hours of initiation of this therapy, the patient complained of giddiness and chest discomfort and was found to have sinus bradycardia on ECG with no acute coronary event. After withdrawing mesalamine, her heart rate normalised within 24 hours and she remained symptom-free. This is a rare case report of severe symptomatic sinus bradycardia due to mesalamine therapy; to our knowledge, only four cases of mesalamine-induced bradycardia have been reported in the literature.