The Sound of Evolution
Pethidine/Meperidine
Mechanism of action:
Pethidine is an opioid and a phenylpiperidine derivative. Pethidine activates μ-opioid receptors in the central and peripheral nervous systems. Through Gi/o proteins, it inhibits adenylyl cyclase and reduces cAMP production, which in turn suppresses presynaptic voltage-gated Ca²⁺ channels, preventing calcium ions from entering the cell. This decreases the release of pain-related neurotransmitters such as glutamate and substance P and reduces pain signal transmission. It also activates postsynaptic potassium channels, causing neuronal membrane hyperpolarization.
Reference(s):
1. Ikeda T et al. (1997). The effect of opioids on thermoregulatory responses in humans and the special antishivering action of meperidine. Ann N Y Acad Sci.
2. Kurz M et al. (1993). Naloxone, meperidine, and shivering. Anesthesiology.