How do penicillins work?

Penicillins are a group of antibacterial drugs that attack a wide range of bacteria. They were the first drugs of this type that doctors used. The discovery and manufacture of penicillins have changed the face of medicine, as these drugs have saved millions of lives.

Penicillium fungi are the source of penicillin, which people can take orally or via injection.

People across the globe now widely use penicillins to treat infections and diseases.

Fast facts on penicillin

  • Penicillins were the first antibiotic that doctors used.
  • There are several antibiotics in the penicillin class.
  • Experts credit Alexander Fleming with discovering penicillins.
  • Penicillin works by interfering with bacteria cell walls.
  • Less than 1 percent of people are dangerously allergic to penicillin.

Function

Drugs in the penicillin class work by indirectly bursting bacterial cell walls. They do this by acting directly on peptidoglycans, which play an essential structural role in bacterial cells.

Peptidoglycans create a mesh-like structure around the plasma membrane of bacterial cells, which increases the strength of the cell walls and prevents external fluids and particles from entering the cell.

When a bacterium multiplies, small holes open up in its cell walls as the cells divide. Newly-produced peptidoglycans then fill these holes to reconstruct the walls.

Penicillins block the protein struts that link the peptidoglycans together. This prevents the bacterium from closing the holes in its cell walls.

As the water concentration of the surrounding fluid is higher than that inside the bacterium, water rushes through the holes into the cell and the bacterium bursts.

History

People generally attribute the discovery of penicillins to Alexander Fleming. The story goes that he returned to his laboratory one day in September 1928 to find a Petri dish containing Staphylococcus bacteria with its lid no longer in place.

The dish had become contaminated with a blue-green mold called Penicillium notatum. Fleming noted that there was a clear ring surrounding the mold where the bacteria had been unable to grow.

By discovering this mold and recognizing its use, Fleming set the wheels in motion to create one of the most useful drugs in medical history.

In March 1942, Anne Miller became the first civilian to receive successful treatment with penicillin. She narrowly avoided death following severe infection after a miscarriage.

Although Fleming technically discovered the first antibiotic, scientists had to do a lot of work before penicillins could become available for general use.

Scientists with a superior laboratory and a deeper understanding of chemistry than Fleming carried out the bulk of the work. Howard Florey, Norman Heatley, and Ernst Chain performed the first in-depth and focused studies on the drug.

In Fleming’s Nobel Prize acceptance speech, he warned that the overuse of penicillins might, one day, lead to bacterial resistance. This has since become a problem.

Resistance

Contrary to popular opinion, it is not the person who develops resistance to penicillins but the bacteria itself.

Bacteria have been around for billions of years. During this time, they have endured extreme environments and, as a result, are highly adaptable. They also regenerate very rapidly, making relatively quick genetic changes possible across a population.

There are three common ways in which bacteria can develop an immunity to penicillin:

  • Penicillinase: Bacteria are sometimes able to produce penicillinase, an enzyme that degrades penicillins. This ability can spread throughout the bacterial population via a small ring of DNA in a process called conjugation. This is the bacterial equivalent of sexual reproduction, where individual organisms share new genetic information between them.
  • Altered bacterial structure: Some bacteria can subtly change the format of the penicillin-binding proteins in their peptidoglycan wall so that penicillins can no longer bind to it.
  • Penicillin removal: Other bacteria develop systems to export penicillins. Bacteria have efflux pumps that they use to release substances from the cell. The repurposing of some of these pumps can allow the cell to dispose of penicillins.

Side effects

The most commmon side effects of taking penicillins include:

Less common side effects include:

  • shortness of breath or irregular breathing
  • joint pain
  • sudden lightheadedness and fainting
  • puffiness and redness of the face
  • scaly, red skin
  • vaginal itching and discharge, due to either a yeast infection or bacterial vaginosis
  • sore mouth and tongue, sometimes with white patches
  • abdominal cramps, spasms, tenderness, or pain

Rare side effects include:

  • anxiety, fear, or confusion
  • a sense of impending doom
  • hallucinations
  • yellowing of the eyes and skin
  • a sore throat
  • unusual bleeding
  • diarrhea and reduced urination
  • convulsions

Risks

Although the use of penicillins is widespread, some issues or contraindications can occur, as with any drug:

  • Breast-feeding: People who are breast-feeding may pass small amounts of penicillin to the child. This can result in the child experiencing allergic reactions, diarrhea, fungal infections, and skin rash.
  • Interactions: Some other drugs can interact with penicillins. Checking with a doctor before taking multiple medications is vital.
  • Bleeding problems: Some penicillins, such as carbenicillin, piperacillin, and ticarcillin, can make pre-existing bleeding problems worse.
  • Oral contraceptives: Penicillins can interfere with birth control pills, increasing the risk of unwanted pregnancy.
  • Cystic fibrosis: People with cystic fibrosis are more prone to fever and skin rashes when taking piperacillin.
  • Kidney disease: Individuals with kidney disease have an increased risk of side effects.
  • Methotrexate: Methotrexate disrupts cell growth and can treat several conditions, including leukemia and some autoimmune diseases. Penicillins prevent the body from disposing of this drug, potentially leading to severe complications.
  • Phenylketonuria: Some stronger, chewable amoxicillin tablets contain high levels of aspartame that the body converts to phenylalanine. This is dangerous for anyone with phenylketonuria.
  • Gastrointestinal problems: Patients with a history of stomach ulcers or other intestinal diseases might be more likely to develop colitis when taking penicillins.

Penicillin allergy

Some people have an allergy to penicillins.

Allergic reactions to penicillin typically lead to hives, wheezing, and swelling, particularly of the face.

Around 10 percent of people report an allergy to penicillins but the real figure is closer to 1 percent, and only around 0.03 percentTrusted Source exhibit life-threatening allergic responses.

Alcohol and penicillin

Certain antibiotics, such as metronidazole and tinidazole, have severe reactions with alcohol. However, this is not the case with penicillins.

Takeaway

Penicillins have saved countless lives throughout their history of use in medicine. However, doctors are now worried about the increase in antibiotic resistance. Only time will tell how the antibiotics of the future will overcome this hurdle.

See more here: medicalnewstoday.com

Header image: AARP

Please Donate Below To Support Our Ongoing Work To Defend The Scientific Method

PRINCIPIA SCIENTIFIC INTERNATIONAL, legally registered in the UK as a company incorporated for charitable purposes. Head Office: 27 Old Gloucester Street, London WC1N 3AX. 

Trackback from your site.

Comments (8)

  • Avatar

    sir_isO

    |

    I’ve personally endured dozens of life-threatening infections, abscesses without any pharma. Penicillin is garbage.

    Just copy pasting the composition of something effective.
    tinospora cordifolia – 49mg
    moringa pterygosperma – 16mg
    balsamodendron mukul – 162mg
    rubia cordifolia – 32mg
    emblica officinalis – 16mg
    shankh bhasma – 30mg
    glycyrrhiza glabra – 6mg
    maharasnadi quath – 60mg
    cinnamomum xeylanicum – 5mg
    asparagus racemosus – 5mg

    If you analyze the constituents it might be telling about why it works well, but I wouldn’t know. Finding info about that sort of stuff is obviously difficult.

    Anyway, you never need penicillin.

    Reply

    • Avatar

      sir_isO

      |

      Oh right, that’s just the balance.

      Typically I’d use around 3-8x that a day, for around 3-5 days, depending on the severity of the infection, usually more initially.

      Reply

      • Avatar

        sir_isO

        |

        I mean, of the 3-8x a day, usually closer to the higher end of that, initiially.

        So like maybe 6-8 first day, 4-6 second day, 3-5 third day.

        Reply

      • Avatar

        LLOYD

        |

        You may not need it, but others have and survived because of it. Your way is not the only way.

        Reply

  • Avatar

    sir_isO

    |

    Essential iodine, was conveniently demonized in favour of non-essential, toxic penicillin, based on pasteur/rockefeller methodology. It goes REALLY well with fluorine, chlorine, benzene and such.

    Did you know almost any toxin you can think of can be an antibiotic? Glyphosate, for instance, a metal chelator. But, due to its toxicity, it’s also an antiobitic! Other than in all your “food”.

    Reply

    • Avatar

      sir_isO

      |

      “It goes REALLY well with fluorine, chlorine, benzene and such.”

      Oh sorry, just in case that might be confusing, I didn’t mean that it essential iodine goes well with that stuff. I meant, the “antibiotic” power of something like penicillin is greatly increased, such as in common modern antibiotic formulations so readily featuring unessential, toxic, corrosive fluorine despite common iodine deficiencies.

      That’s how “medicine” goes.

      Reply

  • Avatar

    Deck

    |

    “People” who are breast-feeding… would that be women then?

    Reply

  • Avatar

    Joseph Olson

    |

    “CHEST FEEDING PERSON” is the non transphobic description of the lactation condition.

    Reply

Leave a comment

Save my name, email, and website in this browser for the next time I comment.
Share via