Sufentanil

Sufentanil is a synthetic, potent opioid with highly selective binding to μ-opioid receptors. These receptors are widely distributed in the human brain, spinal cord, and other tissues.

In general, opioids decrease cAMP (affecting neural signaling pathways), decrease neurotransmitter release, and cause membrane hyperpolarization, all of which contribute to the relief of painful symptoms.

Opiate receptors are coupled with G-protein receptors and function as both positive and negative regulators of synaptic neural transmission via G-proteins that activate effector proteins. Binding of the opiate receptor leads to the exchange of GTP for GDP on the G-protein complex. As the effector system is adenylate cyclase and cAMP, located at the inner surface of the plasma membrane, opioids decrease intracellular cAMP by inhibiting adenylate cyclase. The release of nociceptive neurotransmitters such as substance P, GABA, dopamine, acetylcholine, and noradrenaline is then inhibited.

Opioids close N-type voltage-operated calcium channels (OP2-receptor agonist), also preventing neurotransmitter release.

Sufentanil and other opioids open calcium-dependent inwardly rectifying potassium channels, resulting in hyperpolarization and reduced neuronal excitability.