I've been asked a question, "What is esketamine and what is racemic ketamine?” There are a few differences between the two, but I want to break it down as simply as possible. In this article, we are going to be talking about the difference between both.

*Why enantiomers are just like a pair of hands*

What are Enantiomers?

It’s important that we briefly explain enantiomers before we touch on the main topic. Enantiomers are two mirror images that are similar, but not identical, to each other. Very much like our left hand and right hand. A pair of enantiomers is called a stereoisomer.

Ketamine is made up of two enantiomers, one is called (S)-ketamine and the other is called (R)-ketamine. That refers to S as in left-handed R as in right-handed, and both complete a stereoisomer. Picture the (S)-ketamine just like your left hand, and (R)-ketamine like your right.

What is Esketamine?

Recently Janssen Pharmaceutical Companies of Johnson & Johnson came up with a medicine called Spravato. This medicine contains one side of the ketamine enantiomer, the (S)-ketamine specifically. Esketamine is an intranasal spray to treat depression.

Want to learn more about intranasal ketamine? If so, read our 5 Things You Need To Know About Intranasal Esketamine For Depression blog post.

What is Racemic Ketamine?

What's interesting about racemic ketamine is that it contains both (S)-ketamine and (R)-ketamine in equal amounts. When you get intravenous ketamine infusions you get both (S)-ketamine and (R)-ketamine.

*Is (S)-ketamine or (R)-ketamine more effective? More research is needed.*

Which is more effective, (S)-ketamine or (R)-ketamine

You may be wondering which one is more effective. No studies as to date have conclusively demonstrated that one enantiomer is better than the other.. While we wait for further research to be performed, we believe that ketamine IV infusions are the most ideal route in a clinical setting because:

In this form, ketamine is 100% bioavailable
The doctor is aware of the exact amount entering the systemic circulation
It allows for the minimal effective dose (i.e. the least amount of medication for the most effective dose)
There is the ability to change the dose or stop the treatment at any time

We explain this in further detail in our blog post Why is Intravenous Ketamine the Best Route?

We hope you found this information to be helpful. Our goal is to educate and inform the public and potential patients. Please let us know if you have any questions!