Singin’ the blues: What can you do with methylene blue?

    NextPrevious

    Singin’ the blues: What can you do with methylene blue?

    Methylene blue (MB) is a heterocyclic aromatic compound, and a basic thiazine dye. We all know that it is used to treat methemoglobinemia. MB is an oxidizing agent, which becomes a reducing agent when NADPH reduces it to leukomethylene blue. It then reduces the iron in methemoglobin, changing it from the ferric (Fe3+) state back to the usual ferrous (Fe2+) state of normal hemoglobin.

     

    Can it also be used to treat hypotension in shock states? It may increase peripheral vascular resistance and positive inotropy by inhibiting nitric oxide synthase and guanylyl cyclase activity. A meta-analysis by Lo et al. examines this question, but the data are sparse. Included in the analysis are two RCTs. They both show that MB increases blood pressure in septic shock at least transiently, but neither shows a statistically significant difference in mortality rates. For other types of shock (e.g. anaphylactic or drug-induced), only case studies exist. Several case studies show improvement in epinephrine-refractory anaphylaxis after administration of MB, but whether improvement was secondary to methylene blue or just coincident remains unknown.

     

    Several case studies also suggest that MB can be used to treat priapism, and with fewer side effects than alpha agonists. Hubler et al. describe a series of cases in which five patients being treated for erectile dysfunction with papaverine, phentolamine, and/or prostaglandin E presented with priapism. All were successfully treated with MB. Potential side effects include transient penile burning and temporary blue discoloration of the penis.

     

    References:

    1. Hoffman RS, Howland MA, Lewin NA, Nelson L, Goldfrank L. A42: Antidotes in depth. In: Goldfrank’s Toxicologic Emergencies. 10th ed. 
    2. Lo JCY, Darracq MA, Clark, RF. A review of methylene blue treatment for cardiovascular collapse. J Emerg Med. 2014;46(5):670-9.
    3. Hubler J, Szanto A, Konyves K. Methylene blue as a means of treatment for priapism caused by intracavernous injection to combat erectile dysfunction. Int Urol Nephrol. 2003;35:519-21.
    4. Vilke GM, Harrigan RA, Ufberg JW, Chan TC. Emergency evaluation and treatment of priapism. J Emerg Med. 2004;26(3):325-9.

     

     

    • Welcome! This is the website for the Mount Sinai Emergency Ultrasound Division. It serves as an information resource for residents, fellows, medical students and others seeking information about point-of-care ultrasound. There is a lot ofRead more

    • renal handling of water

      If you were on a tea & toast diet, how much water would you need to drink before you develop hyponatremia? I haven’t seen anyone work out the numbers before so here are my calculations. AndRead more

    • acute acidemia physiology

      As alluded to in the first post, don’t be fooled by a “normal” potassium in the setting of DKA because osmotic diuresis and H+/K+ exchange means that total body potassium is actually LOW. You all knowRead more

    • renal handling of potassium

      the first symptom of hyperkalemia is death Earlier post covered temporizing measures to counter hyperkalemia — namely, intracellular shift, increasing cardiac myocyte threshold potential. Give furosemide if the patient still urinates and consider dialysis, but then askRead more

    • bicarbonate revisited

      Previous post reviewed the safety of balanced crystalloids in hyper K. But what was up with serum bicarbonate decreasing with saline administration? This post introduces a new way of looking at the anion gap to possiblyRead more

    • hyperkalemia and balanced crystalloids

      Is it safe to give LR or plasmalyte to a hyperkalemic patient (these balanced crystalloids have 4-5 mEq/L K as opposed to 0 mEq/L K in normal saline)? Postponing the discussion of renal handling of potassium toRead more

    • hyperkalemia physiology

      You’ll likely encounter hyperkalemia on your next Resus / Cardiac shift, and you’ll instinctively treat it. But take a moment to review the fascinating physiology behind the “cocktail”! First, consider how K+ is buffered byRead more

    • Slow down your tachycardia (but not really)

      You’re sitting in resus bemoaning the departure of your most beloved attending when suddenly a patient wheels in without warning. The patient looks relatively stable but the triage RN tells you her heart rate wasRead more

    • Otitis externa: use the ear wick!

      Acute otitis externa (AOE) is a common complaint seen in pediatric as well as adult emergency departments. AOE is typically not accompanied by acute otitis media, although concurrent cases are possible. Also called “swimmer’s ear”Read more

    NextPrevious