Clinical Pharmacology of Paracetamol in Infants and Children

Abstract

Paracetamol (acetaminophen) has analgesic and antipyretic effects similar to those of aspirin but has only weak anti-inflammatory effects. It is a nonselective cyclooxygenase inhibitor which acts at the peroxidase site of the enzyme and is thus distinct among the nonsteroidal anti-inflammatory drugs. The major metabolites of paracetamol are paracetamol glucuronide and paracetamol sulphate and the minor metabolites are mercapturic acid cysteine conjugates and N-acetyl-p-benzoquinone imine. The last is a highly reactive intermediate and it reacts with sulfhydryl groups in glutathione and is harmless. Paracetamol may be administered orally, rectally, or intravenously. In infants, the oral dosing of paracetamol consist in a loading dose of 20 mg/kg following by subsequent doses of 10 to 15 mg/kg, and in children, the dose varies with the child age and body-weigh. Paracetamol has been found efficacy and safe in infants and children but it may induce adverse-effects. The elimination half-life of paracetamol is 11.0 and 4.38 hours in more immature preterm infants and in less immature preterm infants, respectively, and it is 3.45 hours in children. Propranolol interacts with drugs. The prophylaxis, treatment, and trials with paracetamol have been investigated in infants and children. Paracetamol may induce toxicity and it crosses the human placenta and migrates into the breast milk in significant amounts. The aim of this study in the review of paracetamol dosing, efficacy and safety, adverse-effects, metabolism, pharmacokinetics, drug interaction, prophylaxis, treatment, trials, toxicity in infants and children, and paracetamol transfer across the human placenta and migration into the breast milk.