Methylene blue and poison-induced hypotension

3 out of 5 stars Methylene blue used in the treatment of refractory shock resulting from drug poisoning. Fisher J et al. Clin Toxicol 2014 Jan;52:63-65 Abstract Refractory shock in drug overdose results mainly from myocardial depression and/or vasodilatation. Bedside echocardiography can be very helpful in sorting out these two mechanisms, each of which might require somewhat different therapy. The best example of this is calcium channel blocker overdose. With myocardial depression, high-dose insulin/euglycemic therapy (HIT) should be considered early on.  However, HIT would not be expected to produce significant vasoconstriction; therefore, with distributive shock, vasopressors (e.g., norepinephrine) may give better results. There is evidence that methylene blue might have a role in reversing distributive shock from anaphylaxis, sepsis, and some poisonings. Methylene blue selectively inhibits the nitric oxide-cyclic guanosine monophosphate pathway that seems to be a key factor in distributive shock. This interesting case report, from Melbourne Australia, describes a 41-year-old man who took a massive overdose of quetiapine (Seroquel). The serum quetiapine level was over 100 times therapeutic.  In addition, he ingested much smaller amounts of carbamazepine, fluoxetine, valproate, and oxazepam. On arrival at hospital, the patient had a systolic blood pressure of 90 mmHg. He was intubated and comatose, with a Glascow Coma Scale of 3. Over the next hours, despite receivin...
Source: The Poison Review - Category: Toxicology Authors: Tags: Medical antidoate distributive shock hypotension methylene blue nitric oxide quetiapine Source Type: news