What is the primary mechanism of action of ketamine?

The primary mechanism of action of ketamine is the inhibition of NMDA (N-methyl-D-aspartate) receptors. NMDA receptors are a subtype of glutamate receptors that play a critical role in synaptic plasticity and memory function, but they are also involved in the transmission of pain and the development of certain psychiatric conditions. By blocking these receptors, ketamine exerts effects that can lead to analgesia (pain relief) and rapid-acting antidepressant properties, which distinguishes it from other anesthetic agents.

Ketamine's unique action on NMDA receptors is also associated with its dissociative anesthetic properties, meaning it can induce a trance-like state while providing pain relief. This particular mechanism underlies its therapeutic applications in both anesthesia and treatment-resistant depression, making it a valuable drug in various medical settings.