Penicillin analogues have opened up new possibilities for doctors in the treatment of infectious diseases. They are more resistant to bacterial enzymes and the aggressive environment of the stomach, have fewer side effects.
About penicillins
Penicillins are the oldest known antibiotic. They have many species, but some of them have lost their relevance due to resistance. The bacteria were able to adapt and became insensitive to the action of these drugs. This forces scientists to create new types of mold, penicillin analogues with new properties.
Penicillins have low toxicity to the body, a fairly widespread use and a good indicator of bactericidal action, but allergic reactions to them are much more common than doctors would like. This is due to the organic nature of antibiotics. Another negative quality can also be attributed to difficulties in combining them with other drugs, especially with similar ones in class.
Story
The first mention of penicillins in literature took place in 1963, in a book about Indian healers. They used mixtures of fungi for medicinal purposes. For the first time in the enlightened world, Alexander Fleming managed to get them, but this did not happen purposefully, but by chance, like all the great discoveries.
Before World War II, British microbiologists worked on the issue of industrial production of drugs in the required volumes. The same problem was simultaneously solved in the USA. Since then, penicillin has become the most common drug. But over time, other groups of antibiotics were isolated and synthesized , which gradually displaced him from the podium. In addition, resistance to this drug began to appear in microorganisms, which complicated the treatment of severe infections.
The principle of antibacterial action
The bacterial cell wall contains a substance called peptidoglycan. The penicillin group of antibiotics affects the synthesis of this protein, inhibiting the formation of necessary enzymes. The microorganism dies due to the inability to renew the cell wall.
However, some bacteria have learned to withstand such a gross invasion. They produce beta-lactamase, which breaks down enzymes that affect peptidoglycans. In order to cope with this obstacle, scientists had to create penicillin analogues that could also destroy beta-lactamase.
Danger to humans
At the very beginning of the era of antibiotics, scientists thought about how toxic they will become for the human body, because almost all living metrics are made up of proteins. But after conducting a sufficient number of studies, we found out that there is practically no peptidoglycan in our bodies, which means that the drug can not cause any serious harm.
Action spectrum
Almost all types of penicillins act on gram-positive bacteria of the genus staphylococcus, streptococcus, corynebacterium diphtheria and the causative agent of plague. Also, their spectrum of action includes all gram-negative microorganisms, gonococci and meningococci, anaerobic bacilli and even some fungi (for example, actinomycetes).
Scientists are inventing more and more types of penicillins, trying to prevent bacteria from getting used to their bactericidal properties, but this group of drugs is no longer suitable for treating nosocomial infections . One of the negative properties of this type of antibiotic is dysbiosis, since the human intestines are colonized by bacteria that are sensitive to penicillin. This is worth remembering when taking medication.
Main types (classification)
Modern scientists offer a modern division of penicillins into four groups:
- Natural that are synthesized by mushrooms. These include benzylpenicillins and phenoxymethylpenicillin. These drugs have a narrow spectrum of action, mainly on gram-negative bacteria.
- Semi-synthetic drugs with resistance to penicillinases. They are used to treat a wide range of pathogens. Representatives: methicillin, oxacillin, nafcillin.
- Carboxypenicillins (carbpenicillin).
- A group of drugs with a wide spectrum of action:
- ureidopenicillins;
- amidopenicillins.
Biosynthetic forms
For example, it is worth giving a few of the currently most common drugs that correspond to this group. Probably the most famous of the penicillins can be considered "Bicillin-3" and "Bicillin-5." They discovered a group of natural antibiotics and were flagships in their category until more advanced forms of antimicrobial drugs appeared.
- Extensillin. Instructions for use states that it is a beta-lactam antibiotic of prolonged action. Indications for its use are exacerbations of rheumatic disease and diseases caused by treponemas (syphilis, frambesia and pint). Available in powders. "Extentsillin" instructions for use does not recommend combining with non-steroidal anti-inflammatory drugs (NSAIDs), since competitive interaction is possible. This may adversely affect the effectiveness of the treatment.
- "Penicillin-Fau" refers to the group of phenoxymethylpenicillins. It is used to treat infectious diseases of ENT organs, skin and mucous membranes, gonorrhea, syphilis, tetanus. It is used as a preventive measure after surgical interventions, to maintain remission in rheumatism, minor chorea, and bacterial endocarditis.
- The antibiotic Ospen is an analogue of the previous drug. It is available in the form of tablets or granules. It is not recommended to combine with NSAIDs and oral contraceptives. Often used in the treatment of childhood diseases.
Semi-synthetic forms
This group of drugs includes chemically modified antibiotics obtained from molds.
- The first on this list is Amoxicillin. Instructions for use (price - about one hundred rubles) indicate that the drug has a wide spectrum of action and is used for bacterial infections of almost any location. Its advantage is that it is stable in the acidic environment of the stomach, and after absorption, the concentration in the blood is higher than that of other representatives of this group. But do not idealize Amoxicillin. Instructions for use (the price may vary in different regions) warns that the drug should not be prescribed to patients with mononucleosis, allergies and pregnant women. Long-term use is not possible due to a significant number of adverse reactions.
- Oxacillin sodium salt is prescribed when bacteria produce penicillinase. The drug is acid-resistant, it can be taken orally, is well absorbed in the intestine. It is rapidly excreted by the kidneys, so it is necessary to constantly maintain the desired concentration in the blood. The only contraindication is an allergic reaction. Available in the form of tablets or in vials, as a liquid for injection.
- The last representative of semisynthetic penicillins is ampicillin trihydrate. Instructions for use (tablets) indicate that it has a wide spectrum of action, affecting both gram-negative and gram-positive bacteria. It is well tolerated by patients, but caution should be given to those who take anticoagulants (for example, people with pathology of the cardiovascular system), since the drug potentiates their effect.
Solvent
Penicillins are sold in pharmacies in the form of powder for injection. Therefore, for intravenous or intramuscular administration, they must be dissolved in a liquid. At home, you can use distilled water for injection, isotonic sodium chloride solution or a solution of two percent novocaine. It must be remembered that the solvent should not be too warm.
Indications, contraindications and side effects
Indications for antibiotic treatment are the diagnoses: croupous and focal pneumonia, pleural empyema, sepsis and septicemia, septic endocarditis, meningitis, osteomyelitis. Bacterial tonsillitis, diphtheria, scarlet fever, anthrax, gonorrhea, syphilis, and purulent skin infections fall into the field of action.
There are few contraindications to treatment with a group of penicillins. Firstly, the presence of hypersensitivity to the drug and its derivatives. Secondly, an established diagnosis of epilepsy, which does not allow the drug to be administered inside the spinal column. As for pregnancy and lactation, in this case the expected benefit should significantly exceed the possible risks, because the placental barrier is permeable to penicillins. While taking the medicine, the child must be temporarily transferred to another method of feeding, since the drug enters the milk.
Side effects can be observed at once on several levels.
From the side of the central nervous system, nausea, vomiting, irritability, meningism, convulsions and even coma are possible. Allergic reactions are manifested in the form of skin rashes, fever, joint pain and swelling. Cases of anaphylactic shock and fatalities are known. Due to the bactericidal action, candidiasis of the vagina and oral cavity, as well as dysbiosis, are possible.
Features of use
With caution, it is necessary to appoint patients with impaired liver and kidney function, with established heart failure. It is not recommended to use them for people prone to allergic reactions, as well as those who have an increased sensitivity to cephalosporins.
If five days after the start of therapy no changes in the patient's condition have occurred, it means that it is necessary to use penicillin analogues or replace the antibiotic group. Simultaneously with the appointment of, for example, the substance "Bicillin-3", care must be taken to prevent fungal superinfection. For this, antifungal drugs are prescribed.
It is necessary to clearly explain to the patient that interruption of the medication without good reason causes the resistance of microorganisms. And to overcome it, you will need stronger drugs that cause severe side effects.
Penicillin analogues have become indispensable in modern medicine. Although this is the earliest open antibiotic group, it still remains relevant for the treatment of meningitis, gonorrhea and syphilis, has a wide enough spectrum of action and mild side effects so that it can be prescribed to children. Of course, like any medicine, penicillins have contraindications and side effects, but they are more than offset by the possibilities for use.