The role of methylene blue in serotonin syndrome: a systematic review.
BACKGROUND
A recent series of case reports has demonstrated a significant, previously unrecognized drug interaction between serotonin reuptake inhibitors (SRIs) and methylene blue (MB).


OBJECTIVE
The authors review the case reports and clinical audits relevant to this interaction and consider the diagnosis of serotonin syndrome in these cases.


METHODS
Articles were obtained from a systematic search of MEDLINE and PsychInfo databases, and from the bibliographies of relevant articles. Studies were considered relevant if the patient received MB and developed an acute confusional state, neuropsychiatric complications, or autonomic instability.


RESULTS
The review identified nine case reports and two retrospective reviews; 26 patients developed an acute confusional state after MB infusion; 24 of these patients were taking an SRI, and 1 was taking clomipramine. Serotonin syndrome was a possible diagnosis in all 25 of these patients.


CONCLUSIONS
SRIs can interact with MB, causing a serious adverse reaction consistent with serotonin syndrome.
Ng
Bradley K W
BK
correspondence and Aged Care Mental Health, Robina Hospital, Gold Coast Health Service District, Locked Bag 15, Robina, QLD 4226, Australia. bkwng@hotmail.com
Cameron
Andrew J D
AJ
D000368:Aged; D000929:Antidepressive Agents, Tricyclic / Q000008:administration & dosage / Q000633:toxicity; D002997:Clomipramine / Q000008:administration & dosage / Q000633:toxicity; D004347:Drug Interactions; D005260:Female; D006801:Humans; D007262:Infusions, Intravenous; D008297:Male; D008751:Methylene Blue / Q000008:administration & dosage / Q000633:toxicity*; D008875:Middle Aged; D011183:Postoperative Complications / Q000139:chemically induced / Q000175:diagnosis; D020230:Serotonin Syndrome / Q000175:diagnosis / Q000209:etiology*; D017367:Selective Serotonin Reuptake Inhibitors / Q000008:administration & dosage / Q000633:toxicity*
D000929:Antidepressive Agents, Tricyclic; D002997:Clomipramine; D008751:Methylene Blue; D017367:Selective Serotonin Reuptake Inhibitors