Hypertensive Crisis Associated with Serotonin Syndrome Following Linezolid Administration: Report of Two Cases

Serotonin syndrome is a potentially life-threatening condition that can occur as a result of the therapeutic use of serotonergic medications or drug interaction. In this study, we describe two cases of serotonin syndrome-associated hypertensive crisis following linezolid use.

The first patient was a 52-year-old female who was admitted due to a diabetic foot infection and pneumonia associated with a decreased consciousness level. Serotonin syndrome occurred 24 hours after starting the linezolid use. Resistant hypertension was the main hemodynamic finding. It could not be controlled with amlodipine, valsartan, prazosin, and nitroglycerin infusion. Resistant hypertension and other symptoms of serotonin syndrome were resolved about 48 hours after discontinuation of linezolid use. The second case was a man with a history of kidney transplant, diabetes, and hypertension. He was admitted to the ICU due to severe COVID-19. Broad-spectrum antibiotics [linezolid, cefepime], and remdesivir was initiated. Following intubation, continuous infusion of fentanyl was used for sedation. Within 24 hours after fentanyl and linezolid initiation, severe agitation, eye clonus, hyperreflexia, hypertension [160-186 /90-110 mmHg], and tachycardia [>100/min] were noted. With the possible diagnosis of serotonin syndrome, fentanyl was discontinued, and morphine was initiated. The patient's symptoms improved 48 hours after discontinuation of fentanyl.

Both patients had a history of well- controlled hypertension. Hypertensive crisis has occurred after recent or concurrent use of serotonergic agents with linezolid. A thorough evaluation of the patient's medical history and current condition can help clinicians prevent this syndrome in critically ill patients.