PCP acts primarily as an antagonist at which receptor?

PCP acts primarily as an antagonist at which receptor?

• A. Dopamine D2 receptor antagonist
• B. NMDA receptor antagonist
• C. GABA-A receptor agonist
• D. 5-HT2 receptor antagonist

Answer: (B)

PCP’s primary action is as a noncompetitive antagonist at NMDA receptors, the glutamate-activated ion channels in the brain. By blocking the NMDA channel, it disrupts excitatory signaling and calcium influx, which leads to the dissociative anesthesia and psychotomimetic effects PCP is known for. This mechanism explains its characteristic profile more than any direct action on dopamine D2, GABA-A, or 5-HT2 receptors. Dopamine changes can occur downstream, but they are not PCP’s defining target, and PCP does not act as a GABA-A agonist or primarily as a 5-HT2 antagonist.

PCP’s primary action is as a noncompetitive antagonist at NMDA receptors, the glutamate-activated ion channels in the brain. By blocking the NMDA channel, it disrupts excitatory signaling and calcium influx, which leads to the dissociative anesthesia and psychotomimetic effects PCP is known for. This mechanism explains its characteristic profile more than any direct action on dopamine D2, GABA-A, or 5-HT2 receptors. Dopamine changes can occur downstream, but they are not PCP’s defining target, and PCP does not act as a GABA-A agonist or primarily as a 5-HT2 antagonist.