Antipyretic analgesics

Antipyretic-analgesics drugs are a class of drugs with antipyretic, analgesic and most also having anti-inflammatory and anti-rheumatic effect. It exerts its antipyretic, analgesic and anti-inflammatory effect primarily by inhibiting the synthesis of prostaglandin in the central nervous system and peripheral tissues. However, for its analgesic effect, it can only be used to clear only weak to moderate pain.

Fever is an intrinsic defense reaction of the body of children with however high temperature fever affecting the body of the children adversely such as causing high-fever seizures with being life-threatening in severe cases. Timely administration of antipyretic-analgesics drugs can reduce the body temperature, alleviate the symptoms and prevent the convulsions and other complications. However, it should be noted that the plummeted temperature and excessive sweating have risks of causing collapse. Therefore, overdose should be avoided. The patients should also drink enough water after taking the drugs. Children of history of febrile convulsions can take it in combination with sedatives such as luminal. In case of fever, early administration of paracetamol tablets can prevent febrile convulsions.

According to the chemical structures, it can be divided into four categories:
1. Aniline; such as phenacetin, acetaminophen and so on.
2. Pyrazolones; such as aminopyrine, dipyrone, phenylbutazone and so on.
3. Salicylic acid; such as aspirin, sodium salicylate.
4. Novel anti-inflammatory analgesics drugs; such as indomethacin, mefenamic acid, ibuprofen and ibuprofen, ketoprofen and so on. This class of drugs has common adverse reactions such as rash, leukopenia, angioedema and anaphylactic shock can occur in small number of patients. Large doses can cause gastrointestinal reactions and liver and kidney dysfunction.

Aspirin has a stimulating effect on the gastrointestinal tract with long-term administration being able to cause gastritis, gastric ulcers and bleeding and inducing bronchial asthma and Reye's syndrome, being manifested as convulsions coma and liver damage. Analgin, in addition to general adverse reactions, occasionally cause severe leukopenia, exfoliative dermatitis and drug fever. Paracetamol class has fewer adverse reactions and is non-irritating to the stomach without causing stomach bleeding except occasional skin rashes and other allergic reactions. However, long-term administration of large doses may have liver and kidney dysfunction. Phenacetin, aminopyrine and other side effects are relative severe, therefore, minimizing the administration of aspirin compound (i.e. APC) class of drugs. Currently there is trend of promoting application of paracetamol and single administration of small amount of water-soluble aspirin.