Penicillin is a powerful antibiotic

Penicillins

Antibiotic obtained from brush mold

In 1928 the Scottish bacteriologist Alexander Fleming accidentally discovered the bactericidal effect of cultures of the brush mold Penicillium chrysogenum (formerly P. notatum; lat. penicilius = Brush). Fleming later extracted the antibiotic active ingredient from this fungal culture and named it penicillin. However, penicillin was not used as a drug until a few years later.

Penicillins: Antibiotic active ingredient

Penicillins are naturally occurring, antibiotic drugs that kill bacteria. They belong to the group of beta-lactam antibiotics. This makes them metabolic products of mold cultures.

In addition to the naturally occurring penicillins, pharmacists also produce the active ingredients biosynthetically and partially synthetically.

Doctors use penicillins to treat bacterial infections to kill the pathogen. They support the body's immune system in defense.

Areas of application of penicillins

Important areas of application for penicillin are:

Doctors sometimes prescribe penicillins as a preventative measure, such as before an operation.

Active substance groups of penicillins

For one thing, there are penicillins Naturally before, on the other hand, pharmacists modify and make the substances semi or fully synthetic here.

Natural penicillins

Overview of natural penicillins

Benzylpenicillin or penicillin G. was the first active ingredient in penicillin to be used to treat a disease. Benzylpenicillin is not acid stable and would lose its effectiveness in the stomach if ingested orally. That is why doctors always give this active ingredient as an injection or infusion. Another disadvantage is sensitivity to the enzyme Pencillinase. If the pathogens produce this enzyme, they can quickly render benzylpenicillin harmless with it. Depot forms of benzylpenicillin (penicillin G) are:

  • Procaine benzyl penicillin
  • Clemizole Benzylpenicillin
  • Benzathine benzyl penicillin

Doctors put benzylpenicillin because of it good tolerance and often have a strong effect against sensitive germs. Especially with the following infections with:

Bio- and semi-synthetic penicillins

The bio- and partially synthetic penicillins include orally effective penicillins, the penicillinase-stable penicillins and the Broad spectrum penicillins.

Oral penicillins how Phenoxymethylpenicillin (Penicillin V) and Propicillin take up by mouth. Azidocillin and phenethicillin (penicillin MV) also belong to this subgroup. They have a similar spectrum of activity as penicillin G. Their advantage is that they are acid-stable. They remain more or less stable when they come into contact with stomach acid. Oral administration is therefore possible. However, they are only half to a quarter of the potency of benzylpenicillin and are also easily rendered ineffective by penicillinase.

Penicillinase-stable penicillins are effective against pathogens that produce the enzyme penicillinase. Substances belong to this subgroup Oxacillin, dicloxacillin and Flucloxacillin. They are only effective against staphylococci. However, this germ is often already resistant to penicillinase-stable penicillins and many other antibiotics.

Broad spectrum penicillins have an extended spectrum of activity. It includes the following penicillins:

  • Aminopenicillins: Amoxicillin, Ampicillin, Bacampicillin, Epicillin, Pivampicillin, Sultamicillin
  • Acylaminopenicillins:Apalcillin, azlocillin, mezlocillin, piperacillin
  • Carboxypenicillins:Carbenicillin, ticarcillin
  • Ureidopenicillins:Azlocillin, piperacillin, mezlocillin

The oral active ingredients Ampicillin and amoxicillin Doctors prescribe especially for infections of the respiratory tract, urinary tract and biliary tract, otitis media, whooping cough and blood poisoning. Mezlocillin is especially against Enterococci effective that cause intestinal infections. Piperacillin develops its effectiveness particularly strongly against Pseudomonas aeruginosa, a problem germ similar to Staphylococcus aureus.

The individual penicillins are also combined with one another during the treatment for a broader spectrum of activity and an optimal result.

Effect of penicillins

Penicillins have the mechanism of action of Beta-lactam antibiotics. They hinder the build-up of the cell wall of the bacterial cells by using the necessary enzyme D-alanine transpeptidase To block. When the cells of the pathogen multiply, this inhibition of the enzyme leads to the cell wall becoming unstable. She tears up. In this way, penicillins kill bacteria.

Penicillins have a bactericidal effect (bactericidal).

Penicillins, however, only act on bacterial cells that divide and multiply, because cell walls only have to be built up during this process of reproduction.

In cells that do not divide, there is no cell wall build-up and penicillin therefore does not find a point of attack. However, these cells are usually rendered harmless by the body's own defenses and do not represent any particular danger.

Penicillins and resistances

Through excessive use of penicillins, but also through mutation, it happens that the bacteria that you want to fight with penicillin become insensitive to the active ingredients. When bacterial cells develop that make the enzyme beta-lactamase, they make penicillins ineffective. For this reason Merdiziner administer penicillins in combination with other substances that influence this beta-lactamase development. These so-called Beta-lactamase inhibitors such as clavulanic acid, sulbactam and tazobactam remove resistance and increase effectiveness.

Side effects of penicillins

Penicillins are generally well tolerated and non-toxic as substances. It happens that penicillins also attack beneficial bacteria in the intestinal flora through their bactericidal effect. The consequences of this are Indigestion, such as diarrhea or vomiting.

After a penicillin or antibiotic treatment, it is advisable to rebuild a healthy intestinal flora. Over-the-counter preparations are available to antibiotic patients for this purpose.

Our product tips for building a healthy intestinal flora: SYMBIOLACT® Comp. | SYMBIOFLOR® 1 drop | LACTO SEVEN tablets

Please consult your doctor or our pharmacists for advice on choosing the right medication.

Another side effect that occurs when taking penicillins is an allergic reaction to the active ingredient. On average, one in 7000 patients is affected. The allergy manifests itself as slight reddening of the skin, rash, vomiting and nausea. In rare cases, an allergic shock occurs.

If you experience side effects, notify your doctor.

Contraindication and interactions with other means

With a well-known allergy Against penicillins or other beta-lactam antibiotics, you refrain from a dose. Pregnant women clarify the individual dose according to the week of pregnancy with the doctor treating you. When taking penicillins, it is advisable to avoid milk or dairy products. The calcium it contains inhibits the absorption of these specific antibiotics, especially the active ingredients ciprofloxacin, doxycycline and norfloxacin. In addition, you should not drink alcohol during treatment with penicillin.

There are also interactions when taking other medications. It is known that penicillins reduce the effectiveness of hormonal contraceptives such as birth control pills.


Our pages are for your information only and are not a substitute for diagnosis and treatment by the doctor.

For information on risks and side effects, read the package insert and ask your doctor or pharmacist.

Despite careful research and the use of reliable sources, errors can sometimes creep into our texts. Help us improve. Send information to: [email protected]


As of: 10/26/2020

For reasons of better legibility, the male form is used in the text for personal designations. It goes without saying, however, that the information relates to members of both sexes.