Introduction
Propofol, known as 2,6-Diisopropyl phenol, is mainly used in the induction and maintenance of general anesthesia, and the sedation in the intensive care patients with auxiliary ventilation therapy. It has the advantages of rapid anesthesia induction, rapid recovery and functional recovery, and low incidence of nausea and vomiting after operation. Propofol is a kind of intravenous total anesthetic. Propofol has been widely used since the 80s in the last century because of its quick effect, short time, quick sobriety and less side effect.
Figure 1 The Chemical structure of propofol.
Pharmacologic action
Propofol mainly acts on synapses, regulates the release of presynaptic membrane transmitters and functions of receptors in the anterior and posterior membrane. Propofol inhibits the release of excitatory neurotransmitters, mainly by inhibiting Na+ channels to reduce the release of glutamic acid (Glu). For norepinephrine (NA), propofol does not competitively inhibit K+ induced Ca2+ influx and induces NA release. Inhibition of acetylcholine has regioselectivity in the brain and inhibition in different parts. For the inhibitory neurotransmitters, the release of gamma-amino butyric acid (GABA) caused by propofol concentration dependent enhancement of K+ can also enhance the release of glycine acid. But it mainly acts on the GABA receptor in the postsynaptic membrane and inhibits excitatory transmission, which seems to be the main mechanism of anaesthesia.
Function
Propofol is the most widely used anesthetic in the clinical application of gynecologic painless surgery because it features of quick effect, strong controllability, short time, quick sobriety, quick sobriety, and not easy to accumulate in human body. In recent years, some other studies have found that Propofol has some other effects, including the effect of anesthesia, including some other effects. Organ protection, inhibition of platelets, immune regulation, postoperative vomiting, control of the status of epilepsy, analgesic and forgetting effects.
Pharmacokinetics and metabolism
Propofol is metabolized mainly in the liver, and there are two metabolic pathways: one is the production of 4-hydroxypropofol under the action of CYP450 enzyme, and then by glucuronization and sulfate metabolism. The other is to produce glucose aluronic acid metabolite (Propofolglucuronide, PG) directly under the catalysis of UDP-glucuronotransferase (UGTs), which is removed from the urine. More than 88% is excreted from the urine with inactive sulfate and/or glucuronide binding, less than 0.3% excreted from the urine in the original form, and less than 2% of the hydroxyl metabolites excreted from the feces.
References:
1. Liu Yang, Guo-ping Yang, Jie Huang, Ran-ran Zhang, Yan Wang. Pharmacokinetics and pharmacodynamics of propofol injection in healthy volunteers. Chin J Clin Pharmacol., 2013, 29(2), 54-57.
2. Jian-hui Zhang, Juan Zhou. Study of Propofol Glucuronidation Metabolism in Human Liver Microsomes. Strait Pharm J., 2018, 30(4), 136-138.
