Antipyretic: Which side effect is small, oral or suppository?

After continuous popular science, netizens now know that there are two kinds of antipyretic drugs widely used in the world, namely [acetaminophen] and [ibuprofen] recommended by the World Health Organization.

Moreover, acetaminophen is the first choice of antipyretic due to its long clinical use time and high safety.

Because acetaminophen has two different dosage forms, oral and suppository, netizens often ask me such questions: [acetaminophen can have suppository for rectal administration, why should there be oral dosage forms? Shouldn’t suppositories have less side effects than oral administration, and wouldn’t they hurt the liver? ]

With this question in mind, let’s compare the absorption and metabolism differences between oral administration and suppository.

Absorption and Metabolism of Oral and Suppository

The main absorption site of oral acetaminophen is in the small intestine. Before entering the whole body blood circulation, it will first pass through the portal vein to reach the liver. When passing through the liver for the first time, most drugs will be metabolized and inactivated, thus reducing the amount of drugs that enter the whole body to work.

The suppository is absorbed in the rectum and enters the whole body blood circulation through two paths: if the plug is deep (about 6 cm away from the anal opening), the drug must reach the liver through the portal vein before entering the whole body blood circulation, and most of it is inactivated, which is the same as oral drugs.

If the plug site is relatively shallow (about 2 cm away from the anal orifice), the drug mainly enters the whole body blood circulation through the inferior rectal vein and the inferior vena cava of the internal iliac vein of the anal vein, without passing through the portal vein or the liver.

The above is only the absorption stage.

After absorption into the whole body blood circulation, the drug will reach the action site to exert its efficacy, and then it will be delivered to the liver through blood circulation to be metabolized and inactivated, which is what we often call the detoxification effect of the liver.

At this stage, the drugs absorbed orally and the drugs absorbed by suppositories should follow the same metabolic pathway, that is to say, the drugs absorbed through suppositories also need liver metabolism and detoxification, so excessive dose or suppositories will also hurt the liver.

Therefore, in terms of safety, the difference between suppository and oral administration is not big, and the side effects are similar. It is safe to use it strictly according to the recommended dosage in the instructions, and overdose will hurt the liver.

Preferred oral dosage form

In clinical treatment of children’s fever, oral acetaminophen is often the preferred dosage form. Suppositories will only be used as substitutes when children cannot take drugs orally due to nausea, vomiting, crying and other reasons.

This is because children often need to accurately calculate the dosage according to their body weight when using antipyretics. Oral solution dosage forms can accurately measure the dosage, while suppositories are often fixed doses such as 125 mg or 150 mg, which is not easy to accurately administer according to individual body weight.

I have seen many mothers find foreign antipyretic suppositories from Shanghai on the Internet. In fact, acetaminophen suppositories are produced in China and can be bought in pharmacies instead of being found in the sea.

I have always advocated that drugs should be bought in China as far as possible, because the drug instructions need to be read from beginning to end before taking drugs, which is also responsible for children, while the drugs returned from Haitao are written in the local language and are easily misused because they cannot understand the instructions.

Tips for using antipyretics

  1. Antipyretic drugs are only considered when the child’s body temperature is above 38.5 degrees, and they are not required to be used below 38.5 degrees. For example, if a child has a fever of 39 degrees this morning, he was given the medicine once and did not burn again until the next morning. In this case, it is not necessary to take the medicine every 4-6 hours in order to prevent repeated fever.
  2. The use of antipyretics should also ensure that children have sufficient liquid intake.

  3. Antipyretics are administered according to the weight of children, not according to age, because the weight of children of the same age varies greatly.

  4. Don’t wake up sleeping children to take medicine, sleep is more important than taking antipyretics.

  5. Do not use cough and cold drugs together with antipyretic drugs, because such drugs often contain the same antipyretic ingredients, which will inadvertently lead to excessive poisoning of children taking antipyretic drugs.

  6. Do not use tableware such as spoons to estimate the amount of medicine to be taken, but use a medicine dispenser or a calibrated syringe to accurately measure the medicine.

  7. Be sure to keep antipyretics out of reach of children. Strawberry or orange-flavored antipyretics are also attractive to sick children. Clinically, children can often see cases of poisoning caused by drinking drugs as beverages.

Author: Ji Lianmei

The article was reprinted by Clove Garden authorized by the author.