Many parents know paracetamol: in the form of suppositories or juice, it helps with fever and pain. But not only children benefit from this well-tolerated drug. At the end of the 19th century, English and German chemists in particular were researching alternatives to the natural painkillers previously used, such as willow bark. The substances acetanilide and phenacetin, newly developed around 1886, proved to relieve pain and even reduce fever.
Effect of paracetamol
Along with acetylsalicylic acid and ibuprofen, acetaminophen is one of the most commonly used analgesics worldwide. Paracetamol is used for mild to moderately severe pain and belongs to the group of so-called cyclooxygenase inhibitors (non-opioid analgesics). Since paracetamol also reduces fever (antipyretic) and is particularly well tolerated, it is used primarily in children. Unlike the other two active ingredients, however, paracetamol is less effective in relieving pain caused by inflammation, for example in rheumatic diseases. Painkillers: which one, when and for what?
Function of the active substance
Paracetamol is also known chemically as N-acetyl-para-aminophenol (abbreviated APAP), 4′-hydroxyacetanilide, or 4-acetamidophenol. Although paracetamol has been used for decades, the exact mechanism of action was unknown for a long time – as is the case with many other drugs. Even today, not every detail has been unraveled. It is now known that paracetamol inhibits the cyclooxygenase Cox-2 – an endogenous substance that is activated in the event of cell damage and boosts the production of prostaglandins that promote inflammation and increase pain. However, since the inhibitory effect of paracetamol is only comparatively weak, other mechanisms must be involved in its effectiveness. However, these have not yet been deciphered. Paracetamol is often offered in combination preparations together with caffeine. This is said to enhance the analgesic effect of paracetamol.
Paracetamol: dosage
Paracetamol is commercially available in various dosage forms. In children, suppositories or juices or syrup are usually used, while tablets and capsules are more common in adults. Infusions are also available. Paracetamol can be taken once or in three to four individual doses per day. There should be at least six to eight hours between taking the single doses. When dosing acetaminophen, it is important not to exceed the maximum recommended dose, as overdose can cause life-threatening liver damage.
- Adults should not take more than eight tablets of 500 milligrams, or a total of four grams per day.
- For children, the paracetamol dose – depending on age – is lower. Recommended per single dose 10 to 15 milligrams of paracetamol per kilogram of body weight with a daily upper limit of 50 milligrams per kilogram of body weight.
Side effects of paracetamol
In the range of recommended dosage, paracetamol is poor in possible side effects and well tolerated. Rarely to very rarely, the following side effects occur:
- Disturbances in blood formation
- Allergic reactions
- Abdominal pain
- Nausea
- An increase in liver enzymes
- A cramping of the airways with shortness of breath
Overdose: danger to the liver
However, an overdose of paracetamol can result in serious side effects. In particular, the liver can be severely damaged if an adult takes more than ten to twelve grams once or more than 7.5 grams daily over a longer period of time (correspondingly smaller amounts in children). For this reason, paracetamol has been available on prescription in Germany since July 2008 in larger packages (from ten grams of the active ingredient); smaller quantities can still be purchased over the counter in pharmacies. Also critical for the liver is the simultaneous use of potentially liver-damaging substances (for example, drugs for seizure disorders) or alcohol abuse.
Interactions of acetaminophen
Paracetamol may interfere with the excretion of other drugs metabolized by the liver, such as the antibiotic chloramphenicol. It should also be noted that the onset of action may be accelerated or slowed by drugs that affect gastric emptying.During blood tests, the doctor should be informed about the intake of paracetamol, as this may influence certain laboratory values (for example, blood sugar, uric acid). During pregnancy and breastfeeding, paracetamol may be taken for a short time and only after consultation with the doctor.
Research on paracetamol
Although paracetamol was first synthesized in 1893, it was not until 1948 that Brodie and Axelrod discovered that this white, odorless powder with a bitter taste was a breakdown product of the two substances mentioned above, acetanilide and phenacetin, and was responsible for their effects. In 1956, paracetamol was introduced to the market as an analgesic. Stinging pain
