[indices] An unusual adverse drug effect - dark green blood

["Leesette Turner" <hamis@iafrica.com>]

 An unusual adverse drug effect - dark green blood
 fascinating adverse drug effect.  Cross posted from national Electronic Library of Medicines as fair use.
  
      Date Published 08/06/2007 
  
      
      Reporter affiliation Hospital Pharmacist 
      Source Lancet 2007; 369: 1972 
  

      Abstract The Vulcan race in the sci-fi TV series Star Trek have green blood, however in all Earth vertebrates it is red. This case report describes a patient who was found during surgery to have a dark green colouration subsequently ascribed to a drug he was taking. He presented with compartment syndrome requiring urgent surgery. On presentation he had no obvious unexpected abnormalities apart from a rather dark complexion. Insertion of an arterial catheter was difficult, but when successful yielded dark, greenish-black blood. Laboratory analysis revealed the presence of sulfhaemoglobin. This is formed when a sulphur atom is incorporated into the porphyrin ring of the haem group of haemoglobin, and is not effective as an oxygen transporter. Its formation can be caused by medications including sulphonamides, and the patient's drug history suggested the source of the problem: he was taking diclofenac, zopiclone, and sumatriptan, which he took in a dose of 200mg daily - well in excess of the recommended. Sumatriptan includes a sulphonamide group. The patient recovered uneventfully from his surgery and was weaned off sumatriptan after discharge. When seen five weeks later, his blood was normal.