Pembrolizumab: Myocarditis.

A 75-year-old man developed myocarditis while being treated with pembrolizumab for metastatic prostate carcinoma and stage IVB adenocarcinoma of the left lung. He had a history of right bundle branch block and chronic pulmonary embolus. The patient received various treatments, including amiodarone, metoprolol, methylprednisolone, prednisone, colchicine, ibuprofen, and cotrimoxazole. His condition improved over time, with his troponin levels increasing during the tapering of prednisone but eventually returning to normal. After completing the prednisone taper, his left ventricular ejection fraction improved, suggesting subacute or chronic pericarditis. [Extracted from the article]