Abstract

Prof. Gian Maria Pacifici*

ABSTRACT

Paracetamol is the active metabolite of phenacetin and has analgesic and antipyretic effects but has only weak anti-inflammatory effects. Paracetamol is a nonselective cyclooxygenase inhibitor which acts at the peroxidase site of the enzyme. In adults, the oral dose of paracetamol is 325 to 650 mg thrice-daily or 4 times-daily and in children it is 10 to 15 mg/kg not more than five doses per day. Paracetamol has been found efficacy and safe and the prophylaxis and treatment with paracetamol and the trials conducted with paracetamol have been reviewed. Different cytochromes P-450 isozymes metabolize paracetamol into N-acetyl-p-benzoquinone-imine a toxic reactive intermediate metabolite. Paracetamol is also conjugated with glucuronic acid by different isoforms of 5’-diphosphate-glucuronosyltransferases. The pharmacokinetics of 1,000 mg paracetamol (Panadol) and 1,000 mg paracetamol plus 60 mg caffeine (Panadol extra) have been studied in healthy volunteers following oral administration. Panadol and Panadol extra are rapidly absorbed as the mean absorption half-life is about 0.35 hours and are rapidly eliminated as the mean elimination half-life is 2.25 hours (Panadol) and 3.60 hours (Panadol extra) (P-value > 0.05). The interactions of paracetamol with drugs, the toxicity induced by paracetamol, and the treatment of paracetamol poisoning have been reviewed. The aim of this study is to review paracetamol efficacy and safely, prophylaxis, treatment and trials conducted with paracetamol. In addition, paracetamol metabolism and pharmacokinetics, the interactions of paracetamol with drugs, the toxicity induced by paracetamol, and the treatment of paracetamol poisoning have been reviewed.