What are the metabolites of acetaminophen?
Acetaminophen is metabolized by conjugation with sulfate and glucoronidate, which are inert and are excreted in the urine. Depending on dose, a fraction of APAP is converted into a highly reactive toxic intermediate, N-acetyl-p-benzoquinone imine (NAPQI) by several P450 cytochromes[4].
How is acetaminophen made?
2.1. Production and occurrence. Paracetamol may be made by acetylation of para-aminophenol (obtained by reduction of para-nitrophenol) with acetic acid or acetic anhydride.
How is NAPQI formed?
The formation of NAPQI may proceed via CYP2E1 [56] and via peroxidases such as prostaglandin hydroperoxidase. The most commonly described mechanism proposes that metabolic activation occurs through N-oxidation of acetaminophen to N-hydroxyacetaminophen followed by dehydration to NAPQI (Figure 25.23) [57].
Is acetaminophen a polymer?
Chemical structure of (a) acetaminophen and (b) HPMC-AS polymer. HPMC-AS consists of a cellulose ring bonded with various R groups that include hydrogen, methyl (M), hydroxypropyl (P), acetyl (A), and succinoyl (S) groups.
Which functional group in paracetamol is responsible for antipyretic action?
The antipyretic effect of paracetamol occurs independent of transient receptor potential ankyrin 1-mediated hypothermia and is associated with prostaglandin inhibition in the brain. Keywords: N-acetyl cysteine; NAPQI; TRPA1; acetaminophen; fever.
What is the pharmacokinetics of acetaminophen?
Pharmacokinetics. Upon ingestion, acetaminophen is rapidly absorbed from the gastrointestinal (GI) tract and quickly distributed throughout the body. Peak plasma concentrations are achieved within 30 to 60 minutes4; food may delay time to peak concentration, but the extent of absorption is not affected.
What is the chemical structure of acetaminophen?
C8H9NO2Acetaminophen / Formula
What are the important functional groups in paracetamol?
Paracetamol contains three functional groups: the hydroxyl group (OH), the amide group (HN-CO-R), and the aromatic group (benzene ring), as shown in Fig. …
What does NAPQI stand for?
N-acetyl-p-benzoquinone imine
NAPQI, also known as NAPBQI or N-acetyl-p-benzoquinone imine, is a toxic byproduct produced during the xenobiotic metabolism of the analgesic paracetamol (acetaminophen). It is normally produced only in small amounts, and then almost immediately detoxified in the liver. N-acetyl-p-benzoquinone imine.
How is NAPQI detoxified?
Detoxification of NAPQI occurs through its binding to the sulfhydryl group of glutathione (GSH) to form APAP-GSH, which is ultimately excreted in the urine as cysteine and mercapturic acid conjugates (APAP-cys) [5,9].
What functional groups are present in paracetamol?
What is the new functional group formed in paracetamol?
Paracetamol (acetaminophen) is sold under the names Panadol® 1 in the UK, Australia and New Zealand and under the name Tylenol® 2 in the USA. Paracetamol (acetaminophen) is an aromatic compound containing an OH (hydroxyl) functional group and a HN-CO-R (amide) functional group.
What type of drug is acetaminophen?
Acetaminophen is in a class of medications called analgesics (pain relievers) and antipyretics (fever reducers). It works by changing the way the body senses pain and by cooling the body.
What are the functional groups in paracetamol?
Paracetamol contains three functional groups: the hydroxyl group (OH), the amide group (HN-CO-R), and the aromatic group (benzene ring), as shown in Fig. … has been found in aquatic ecosystems in the wild.
Is there an alcohol functional group in acetaminophen?
The functional groups in acetaminophen are hydroxyl, aromatic ring, and amide.
What is the structure of acetaminophen?
How does NAPQI differ from paracetamol?
NAPQI, also known as NAPBQI or N-acetyl-p-benzoquinone imine, is a toxic byproduct produced during the xenobiotic metabolism of the analgesic paracetamol (acetaminophen). It is normally produced only in small amounts, and then almost immediately detoxified in the liver.
What is acetaminophen pharmacokinetics?
Pharmacokinetics. Acetaminophen has a high oral bioavailability (88%), it is well absorbed and reaches the peak blood concentrations within 90 minutes after ingestion [5]. APAP is not widely bound to plasma proteins, and has a plasma half-life of 1.5–2.5 hours at the recommended doses [8].