Bradycardia after pulse methylprednisolone therapy in a child—Uncommon side effect of a frequently used drug: A case report

Corticosteroids are potent anti-inflammatory agents used as a mainstay of therapy in most of the rheumatologic disorders. Common side effects of pulse steroid therapy include hypertension, hyperglycemia, seizure, hypokalemia, and infection. We report a case of an 11-year-old girl with polyarticular Juvenile idiopathic arthritis who developed bradycardia following pulse methylprednisolone therapy. On day 2 of methylprednisolone infusion, she developed bradycardia with a heart rate between 50 and 60/min. ECG was suggestive of sinus bradycardia. There was no evidence of dyselectrolytemia (Na—141 mmol/l, K—3.54 mmol/l, Ca—8.72 mg/l) or sepsis. The patient did not receive methylprednisolone on day 3 and vitals continued to be monitored. Her heart rate improved after 12 hours. In the mid of infusion on day 4, again the patient had bradycardia with a heart rate of 50–60/minute. Since she was hemodynamically stable, we continued the infusion, and bradycardia resolved in the next 8 hours. On follow-up after 2 weeks, she had some improvement in joint symptoms and normal heart rate. As per Naranjo adverse drug reaction probability scale, the adverse reaction in our case was probable with a score of 8. Although bradycardia associated with pulse steroid therapy is benign and is usually reversible following cessation of therapy, a baseline heart rate, ECG, and electrolyte level are suggested before infusion as a cautionary measure to minimize serious adverse events.