Paracetamol is a popular and powerful pain reliever worldwide, but is not widely used anywhere in the world. (1) . Paracetamol can also be used to reduce fever. It has analgesic and antipyretic effects very similar to those of aspirin but has no anti-inflammatory effects. The pharmacokinetics, pharmacodynamics and molecular toxicity of paracetamol will be explained below. Pharmacokinetics is the study of how a drug is processed in the body by examining absorption, distribution, metabolism, and excretion. Pharmacodynamics is the mechanism of the drug at the physiological, biochemical and meolecular levels in the body. Recommended dosageFor an adult the recommended oral dose is 325-1000 mg, for a rectal dose it is 650 mg and the total daily dose should not exceed 4000 mg.( 1) For children, depending on age and weight, the Recommended dose is 40-480 mg with no more than 5 doses administered in one day. (2) Administration and absorption Paracetamol can be administered orally, rectally or intravenously. Oral paracetamol is available in tablets/capsules (extended and regular release), chewable tablets, oral granules and liquid suspensions. Rectally it is administered via suppositories and intravenously via IV. Absorption of paracetamol is rapid and is almost completely absorbed from the gastrointestinal tract.(2) 10-25% of the drug binds to serum proteins after a normal therapeutic dose. (2) Peak plasma concentration, which represents the highest level of drug achievable in the blood, is usually achieved within 30 minutes to 2 hours and may be slightly higher with suspensions. The half-life in plasma is 2 hours after a therapeutic dose. (2) The first pass effect (the loss of the drug from liver metabolism) reduces the concentration by approximately 25% and approximately 85% of the dose is found in the urine within 24 hours of oral administration. (2)DistributionParacetamol is distributed uniformly in most body fluids.(2) The drug should bind to plasma proteins, but does so only 20-50% during acute intoxication.(2)MetabolismAt normal therapeutic doses approximately 85-90 The percentage of the compound is metabolised by the liver into sulphate and glucuronide metabolites, the remaining 10-15% undergoes oxidative metabolism which produces the heptotoxic metabolite. ClearanceAdults and children clear the drug differently. (1) In infants and children aged three to nine years, paracetamol is excreted mainly as a conjugated sulfate, probably due to a glucuronide deficiency in children. (2) Paracetamol-glucuronide conjugate formation measured by high-performance liquid chromatography was quantified by the ratio of the area under the plasma concentration-time curve (AUC).