Source: Medicines & Healthcare Products Regulatory Agency (GB) Revision Year: 2022 Publisher: Phoenix Labs, Suite 12, Bunkilla Plaza, Bracetown Business Park, Clonee, Co. Meath., Ireland
Pharmacotherapeutic Group: Anilides
ATC Code: N02BE01
Paracetamol is an aniline derivative with analgesic and antipyretic actions similar to those of aspirin but with no demonstrable anti-inflammatory activity. It does not affect thrombocyte aggregation or bleeding time. Paracetamol is generally well tolerated by patients hypersensitive to acetylsalicylic acid. It produces analgesia by elevation of the pain threshold and antipyresis through action on the hypothalamic heat-regulation center.
Paracetamol is rapidly and almost completely absorbed from the gastrointestinal tract. Peak plasma concentrations occur about 2 to 3 hours after rectal administration. Usual analgesic doses produce total serum concentrations of 5 to 20mcg/ml. Paracetamol is primarily metabolised in the liver by conjugation to glucuronide and sulphate. A small amount (about 3-10% of a therapeutic dose) is metabolised by oxidation and the reactive intermediate metabolite thus formed is bound preferentially to the liver glutathione and excreted as cystein and mercapturic acid conjugates.
Paracetamol is excreted in the urine mostly as metabolites; 2-4% is excreted unchanged. The average elimination half life is 1 to 4 hours; half life is slightly prolonged in neonates (2.2 to 5 hours) and in cirrhotics.
The overall elimination rate constant for paracetamol in children, from birth to 12 years of age, is the same as for adults but neonates have diminished capacity to form glucuronide conjugates of paracetamol.
Conventional studies using the currently accepted standards for the evaluation of toxicity to reproduction and development are not available.
© All content on this website, including data entry, data processing, decision support tools, "RxReasoner" logo and graphics, is the intellectual property of RxReasoner and is protected by copyright laws. Unauthorized reproduction or distribution of any part of this content without explicit written permission from RxReasoner is strictly prohibited. Any third-party content used on this site is acknowledged and utilized under fair use principles.
