Cisatracurium. The reason each NMB molecule here has a different color is because I have synesthesia.


A molecule of cisatracurium. Wikipedia's molecule is WRONG. Because I could find no high quality pictures of the real cisatracurium molecule, I made this one myself. Click to see it in better detail.


Cisatracurium was officially approved by the FDA on December 15th, 1995. It's the youngest NMB that they currently use. It's also called Nimbex, which stands for "excellent neuromuscular blocker," or if you would prefer the letters to be in the correct order, you could say "neuromuscular blocker of excellence."

Cisatracurium is one of the 10 atracurium stereoisomers. Unlike atracurium, which is a mixture of all 10, cisatracurium is only the cisatracurium isomer. It is the cis-cis isomer of atracurium. The true shape of this beautiful isomer is difficult to visuallize with only the 2-D image of the molecule, so here's a link to a 3-D model of cisatracurium.

Cisatracurium in 3-D

The ED95 for cisatracurium is 0.05mg/kg, and a good intubating dose is 4x that, 0.2mg/kg. Intubation conditions good to excellent within 90 seconds, although it might last for a bit afterwards. Otherwise, a normal dose takes about 3 minutes to fully kick in.


A picture of a surgical drape holder advertising cisatracurium

Cis is more potent than atra, has a slower onset, and lasts slightly longer. However, it is still considered to be intermediate onset and intermediate duration. It is on the longer lasting end of the group of intermediate duration NMBs though, and is sometimes said to be of "intermediate-long" duration.

It also has pretty much no side effects, and it undergoes Hoffmann elimination, meaning it doesn't rely on the liver or kidneys to be broken down, making cisatracurium a truly excellent neuromuscular blocker indeed.