December 8, 2022

This video explains:

Acetaminophen is also called paracetamol and it is a popular and widely available over-the-counter analgesic and antipyretic trock analgesic is a drug that relieves pain and the antibiotic is a drug that reduces fever now before moving to the metabolism of the acetaminophen first let me just explain the phases of fer the drug metabolism which are essential to

Understand what exactly the metabolism of this term 11 is so when a drug enters our body the ultimate goal of our body is to make it hydrophilic so by making it hydrophilic what a body will do is that it will make the drug more soluble in water so that it will be easy for it to get eliminated from the body now to do so there are two phases of the drug metabolism

Which our body performs they are phase one metabolic reactions drug metabolism reactions and the phase two drug part of ilysm reactions in the phase one drug metabolism reactions the reactions which usually take place are the oxidation reduction and the hydration reactions so what basically happens in this phase is that the there are some certain groups on

Present on the drug which gets exposed so that the phase two reactions can occur accordingly to that a group that has been exposed now the phase two reactions will further lead onto the conjugation reactions so what basically happens in phase two my drug metabolism reactions is that the conjugation of the drug takes place so that it becomes more hydrophilic and

Ultimately gets eliminated from the body now talking about the metabolism of acetaminophen so this is the acetaminophen molecule which have an acetyl group present on this position the para position when this acid of envelope n enters our body about ninety percent of it gets converted into its sulfate conjugates and gluconate conjugates these surveyed conjugates

Are formed by the action of sulphur transferases on them which leads to the conjugation of sulfate group with the acetaminophen and glue chloride conjugates are formed by the action of the enzyme udp blue chromis i’ll transferase which attaches the blue kronite group to the acetaminophen molecule these conjugations result in increased hydrophilicity this thing

Creates the hydrophilicity of the drug molecules are now able to be more soluble in water and hence they can be easily eliminated out of the body also about five percent of the drug is directly eliminated from the body via geron however about five percent of the drugs gets converted into the toxic form of acetaminophen which is na p qi that is n acetyl parabens

Ooh quinone amine now this happens through the enzyme cytochrome p450 mono oxygenase systems which are the enzyme components of the phase one reactions however this na pqi combines immediately with glutathione to form a non-toxic mic apatite conjugate which can be eliminated from the body now if there is the acetaminophen overdose what happens when there is over

Dose of acetaminophen the glutathione stores are depleted why this happens because if there will be more of acetaminophen there will be more of na pqi which will lead to more of the conjugation of glutathione with a to make it eliminated from the body this is because the rate of utilization of glutathione exceeds its rate of formation and hence there is depletion

Of gluten and stores in the body if the gluten high levels fall below 30% of the normal the highly reactive na pqi can bind instead to the cellular macromolecules that contains cysteine and this toxic form will lead to the injury to cells and you

Transcribed from video
Metabolism of Acetaminophen (paracetamol) By BioMed GP