A 54-year-old woman developed nocturnal sinus bradycardia during treatment with methylprednisolone and methylprednisolone sodium succinate.

The woman was admitted for re-exacerbation of multiple sclerosis. She was started on IV methylprednisolone 1g in 250mL3 of 0.9% normal saline administered daily over a 3 hour period for 5 days. She developed sinus bradycardia, on the night of the day 3. However, her BP was normal. During her subsequent hospitalisations for exacerbation of multiple sclerosis, she developed bradycardia with IV administration of methylprednisolone sodium succinate [dosage not stated]. As she was asymptomatic, the IV methylprednisolone administration was continued and she was closely monitored. There was no deterioration in her condition, she completed the course of IV methylprednisolone following which she was switched to oral prednisone on day 5. She tolerated the IV administration and developed no adverse effects while undergoing oral prednisone taper. Sinus bradycardia resolved after the methylprednisolone therapy was completed.

Author comment: "Our patient did not have a prior history of cardiac disease, and the nocturnal sinus bradycardia was noticed while she was receiving intravenous methylprednisolone, suggesting that intravenous methylprednisolone induced this adverse effect."