Paracetamol 500mg paracetamol tablets treated with fever, analgesic (10 blisters x 10 tablets)

paracetamol reduces the body temperature, but rarely reduces the body temperature in normal people. The drug acts on the hypothalamus causing cooling, increasing heat due to vasodilation and increasing peripheral blood flow.

Pharmacokinetics

absorption

Paracetamol is quickly absorbed and almost completely through the gastrointestinal tract. Carbohydrate -rich foods reduce the absorption rate of paracetamol.

Distribution

After drinking with treatment dose, peak plasma concentration reaches 30 to 60 minutes.

Paracetamol is distributed quickly and evenly in most body tissues. About 25% Paracetamol in the blood combined with plasma protein.

Metabolism

Paracetamol has N - hydroxylation of cytochrom P450 to create N - Acetyl - Benzoquinonimin (NAPQ), an intermediary with high reaction. This metabolic substance normally reacts with sulfhydryl groups in glutathion and is dull.

However, if taking high doses of paracetamol, this metabolic is formed in sufficient amount to exhaust the glutathion of the liver; In that situation, NAPQ is not connected with glutathion toxic to liver cells, leading to inflammation and can lead to liver destruction.

Elimination

Paracetamol's plasma semi -discharged time is 1.25 - 3 hours, which can last for toxic doses or in patients with liver damage.

After the treatment dose, 90 - 100%of the urine can be found on the first day mainly after the liver with glucuronic acid (about 60%), sulfuric acid (about 35%) or cysteine ​​(about 3%); It also detects a small amount of hydroxyl metabolites - chemical and reducing acetyl. Young children are less likely to match Glucuronid with drugs than adults.

Be cautious when using

paracetamol is relatively non -toxic to the dose of treatment, and when used under the guidance of a physician. However, overdose of paracetamol is the main cause of acute liver failure. Using many preparations containing paracetamol (acetaminophen) and can lead to harmful consequences (such as paracetamol overdose).

Serious, fatal skin reactions include Stevens - Johnson syndrome, poisoned epidermal necrosis (Ten), all -body pustular syndrome (AGEP: Acute Generalized Exanthematous), Lyell syndrome but rarely occurring with paracetamol, often does not depend on the effects of other drugs. While other analgesic and antipyretic (such as NSAID) can cause similar reactions, cross -sensitive with paracetamol does not occur.

Patients need to stop using paracetamol and see a physician as soon as they see rash or other manifestations in the skin or sensitive reactions during treatment. Patients with a history of such reactions should not be used in preparations containing paracetamol.

Sometimes skin reactions include itching and urticaria; Other sensitive reactions include larynx edema, angioedema and anaphylactic reactions that may rarely occur. Platelets, leukopenia, and all bloody hematuria have occurred with the use of p - aminophenol derivatives, especially when used for large doses. Neutral leukopenia and thrombocytopenic hemorrhage occur when using paracetamol. Rarely loss of granulocytes in patients using paracetamol.

People with phenylceton - urinary (that is, gene deficiency determines the status of phenylalanin hydroxylase) and people must limit the amount of phenylalanin that must be warned as some paracetamol preparations containing Aspartam, which will metabolize in the stomach - the intestine of Phenylalanin after drinking. Some forms of paracetamol drugs on the market containing sulfit can cause allergic reactions, including anaphylaxis and life -threatening or less serious henses in some hypersensitivity people. Common in patients with asthma more in asthma.

Be cautious when using paracetamol for people with liver failure, kidney failure, alcoholic, chronic malnutrition or dehydration. Avoid high doses, prolonged and intravenous use for people with liver failure.

Must use paracetamol carefully in patients with anemia before, because purple blue may not manifest clearly, although high concentrations at a dangerous level of methemoglobin in the blood.

Drinking plenty of alcohol can cause toxicity to the liver of paracetamol, should avoid or limit drinking alcohol.

The ability to drive and operate machinery

There is no report.

Pregnancy

should only use paracetamol in pregnancy when really necessary.

Demonstrate period

Research in nursing mothers, using paracetamol does not see ADR in breastfeeding.

Medicinal interaction

anticoagulant drugs: Paracetamol long -term taking slightly slightly anticoagulant effects of COMAARIN and indandion derivatives. Research data is still conflicting and also doubted about this interaction, so paracetamol is preferred than salicylate when it is necessary to relieve mild analges or reduce fever for patients using cooumarin or indoplasm.

It is necessary to pay attention to the possibility of serious heat lowering the patient and phenothiazine and cooling (such as paracetamol).

Overdoor and long -term drinking can increase the risk of Paracetamol's liver toxicity.

Anti -convulsions (including Phenytoin, Barbiturate, Carbamazepin) that causes enzyme induction in the liver microsom, can increase the toxicity of the liver toxicity of paracetamol due to increased drug conversion into liver toxic substances. In addition, simultaneous use of isoniazid with paracetamol can also lead to an increase in the risk of toxicity to the liver, but it has not been determined the exact mechanism of this interaction.

The risk of paracetamol causes liver toxicity significantly increases in patients who take paracetamol dose larger than the recommended dose while taking anti -convulsions or isoniazid. Often do not need to reduce the dose in patients with simultaneous doses of paracetamol treatment and anti -convulsions; However, patients must limit the use of paracetamol while taking anti -convulsions or isoniazid.

Probenecid may reduce paracetamol elimination and reduce the sale time in plasma of paracetamol.

Isoniazid and tuberculosis drugs increase the toxicity of paracetamol for the liver.