As a parent, you should know a few things about "cephalosporin"

"Cephalosporin", or cephalosporin antibiotics, is often used as one of the first choice drugs for children to fight bacterial infections. I believe that parents are familiar with it. But how much do you know about it? The various types of cephalosporins on the market look the same but seem to be different. Let's take a closer look.

1. Why do pediatricians like to use cefuroxime?

Two words: safe and effective!

① Safety

Here we need to briefly understand its mechanism of action: Cephalosporin is a type of antibiotic obtained by semi-synthetically modifying the side chain of natural cephalosporin C obtained by culturing Cephalosporin. It belongs to the same class of β-lactam antibiotics as penicillin, and they have similar mechanisms: by interfering with the synthesis of bacterial cell walls, causing them to swell, lyse, and then inactivate. Since human cells do not have cell walls, they have no harmful effect on human cells.

Low allergic reaction rate: Compared with penicillin, although the two have similar structures and can also cause allergic reactions, the rate of allergic reactions is lower than that of penicillin, and the incidence of anaphylactic shock is even lower.

②Effective

Of course, as a drug, it must have a therapeutic effect. Cephalosporin is a bactericidal agent that can kill bacteria if the concentration is sufficient; it has a broad antibacterial spectrum and can be distributed in various parts of the body, and has effects on Gram-positive bacteria (such as Staphylococcus aureus, which can cause bronchopneumonia, skin infections, etc.) and Gram-negative bacteria (such as Haemophilus influenzae, which can cause meningitis, bacteremia pneumonia, etc.).

Compared with penicillin, its resistance rate is low. Bacteria produce some enzymes that destroy antibiotics during evolution, which can cause resistance to certain antibiotics, and cephalosporins are relatively stable to most of these enzymes produced by bacteria.

2. How many generations of cephalosporins are there? Are there any differences between them?

① There are more than 30 commonly used cephalosporins, which are divided into five generations according to their development order and antibacterial properties:

In short, cephalosporins:

※ Antibacterial activity against Gram-positive bacteria: first generation > second generation > third generation < fourth generation < fifth generation;

※Antibacterial activity against Gram-negative bacteria: each generation is stronger than the previous one;

※ Stability to enzymes: each generation is more stable than the previous one;

※Nephrotoxicity: Lower with each generation.

3. Is it not necessary to do skin test for cephalosporin?

Yes!

In 2021, the National Health Commission issued the "Guidelines for Skin Testing of β-lactam Antimicrobial Drugs (2021 Edition)", which clearly stated that routine skin testing of cephalosporins is not recommended, and provided relevant evidence-based evidence. Simply put, this is because cephalosporin skin tests are prone to false positives and false negatives, that is, redness and swelling of the skin during the skin test does not necessarily mean that cephalosporins cannot be used, and the lack of reaction in the skin test does not mean that there will be no allergic reaction after the cephalosporin injection. This kind of skin test makes the results irrelevant and loses the meaning of the skin test.

Our hospital has promptly cancelled the requirement for routine skin testing of cephalosporin drugs, except for patients with a clear history of penicillin or cephalosporin type I (immediate) allergy and those for whom skin testing is clearly specified in the drug instructions (e.g., ceftriaxone sodium for injection).

4. Take cefuroxime with alcohol, and leave right away?

People now have a basic understanding: cephalexin + alcohol = disulfiram-like reaction.

However, not all cephalosporins will cause disulfiram-like reactions, and, in addition to cephalosporins, some other drugs can also cause disulfiram-like reactions.

Disulfiram-like reaction: also known as disulfiram-like reaction, refers to the inhibition of liver acetaldehyde dehydrogenase by disulfiram or drugs with the same mechanism of action, which hinders alcohol metabolism, leading to accumulation of acetaldehyde in the body, and thus causing a series of symptoms. In mild cases, there will be weakness, dizziness, drowsiness, hallucinations, body flushing, headache, nausea, vomiting, and low blood pressure. In severe cases, there may be severe reactions such as respiratory depression, collapse, convulsions, heart dysfunction, and even anaphylactic shock, which is life-threatening.

Drugs that cause disulfiram-like reactions need to have such structures: methylthiotetrazol side chain and methylthiotriazine side chain. Cefuroxime axetil, cefprozil, cefdinir, etc., which are often used in outpatient clinics, do not contain this structure, so disulfiram-like reactions will not occur! However, cefoperazone, ceftazidime, ceftriaxone, cefotaxime, cefixime, cefaclor, cefazolin, ceftizoxime, cephalexin, etc. may occur. Cefoperazone is the drug with the highest incidence of disulfiram-like reactions reported in the literature among cephalosporins. It should be noted that the severity of the disulfiram reaction is proportional to the drug dosage and the amount of alcohol or ethanol used.

In addition to cephalosporins, some other drugs can also produce disulfiram-like reactions when reacting with ethanol, such as ketoconazole, co-sulfamethoxazole, metronidazole, chloramphenicol, norfloxacin, isoniazid, insulin, gliclazide, etc. We need to pay special attention to this in our daily lives.

Of course, the alcohol here does not just refer to ethanol, but also includes some alcohol-containing medicines, foods and operations, etc., which require special attention when taking them, such as: Oulongma Drops, Huoxiang Zhengqi Water, Compound Licorice Oral Liquid, Hydrocortisone Injection, Nimodipine Injection, Thromboton Injection and other medicines; beer, red wine, rice wine and other alcoholic beverages; food such as chocolate with alcohol filling, drunken crab, drunken goose; alcohol baths, ear drops and other operations.

5. What precautions should be taken when taking cephalosporins?

① Although cephalosporins are safe and effective, we cannot abuse them in large quantities and must treat them symptomatically, otherwise there will be a large number of drug resistance in the near future and there will be no drugs available;

② Although not all cephalosporin antibiotics will produce disulfiram-like reactions, for safety reasons, we non-medical personnel should still remember: never use cephalosporins before or after drinking alcohol, especially the elderly.

③ When taking the drug with other drugs, you need to carefully check the [Interaction] section in the drug instructions to avoid interactions that may cause harm to the human body. If necessary, keep a certain amount of time between the two drugs or consult a doctor or pharmacist.

Author information: Xue Dan, Shanxi Children's Hospital