Therapeutic cyproheptadine regimen in serotonin syndrome: Complications after cardiovascular surgery

Serotonin syndrome can be a life‐threatening condition that occurs from the overactivity of serotonin in the central nervous system. This report describes the use of cyproheptadine for the management of serotonin syndrome in a patient taking fluoxetine and bupropion, who received methylene blue for vasoplegia syndrome. A 61‐year‐old female taking fluoxetine and bupropion preoperatively was given a total of three doses of methylene blue 100 mg IV within a brief time frame during and after a planned coronary artery bypass graft surgery. Postoperatively, the patient was not following commands, was agitated and confused, febrile with diaphoresis, tachycardic, had muscle rigidity, and horizontal ocular clonus. The patient's presentation was most consistent with serotonin syndrome due to a drug–drug interaction. Cyproheptadine and supportive care were used successfully to treat serotonin syndrome, and the patient was discharged home 14 days postoperatively. Based on the literature, there is no standardized method of weaning cyproheptadine when used for serotonin syndrome. The patient in our case received a total of 188 mg of cyproheptadine over the course of 10 days and did not experience any side effects. This case highlights a potential dosing regimen that can be used for other patients.