Analogues of penicillin have opened up new opportunities for physicians in the treatment of infectious diseases. They are more resistant to bacterial enzymes and the aggressive environment of the stomach, and have fewer side effects.
About penicillins
Penicillins are the oldest known antibiotics. 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, analogues of penicillin, with new properties.
Penicillins have low toxicity to the body, a fairly wide 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 the difficulty in combining them with other drugs, especially those similar in class.
History
The first mention of penicillins in the literature took place in 1963, ina book about Indian medicine men. 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 accident, like all great discoveries.
Before the Second World War, British microbiologists worked on the issue of industrial production of drugs in the required volumes. The same problem was solved in parallel in the United States. Since then, penicillin has become the most common drug. But over time, other groups of antibiotics were isolated and synthesized, which gradually replaced him from the podium. In addition, resistance to the drug began to develop in microorganisms, making it difficult to treat severe infections.
The principle of antibacterial action
The cell wall of bacteria contains a substance called peptidoglycan. The penicillin group of antibiotics affects the synthesis of this protein by inhibiting the formation of the necessary enzymes. The microorganism dies due to the inability to renew the cell wall.
However, some bacteria have learned to resist such a brutal invasion. They produce beta-lactamase, which destroys enzymes that affect peptidoglycans. In order to cope with this obstacle, scientists had to create analogues of penicillin that can destroy beta-lactamase too.
Danger to humans
At the very beginning of the era of antibiotics, scientists thought about how toxic they would become to the human body, because almost allliving 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 cannot cause any serious harm.
Action spectrum
Practically all types of penicillins affect 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 new types of penicillins, trying to prevent bacteria from getting used to their bactericidal properties, but this group of drugs is no longer suitable for the treatment of nosocomial infections. One of the negative properties of this type of antibiotics is dysbacteriosis, since the human intestine is colonized by bacteria that are sensitive to the effects of penicillin. This is something to keep in mind when taking medication.
Main species (classification)
Modern scientists propose a modern division of penicillins into four groups:
- Natural, which are synthesized by mushrooms. These include benzylpenicillins and phenoxymethylpenicillin. These drugs have a narrow spectrum of action, mainly against gram-negative bacteria.
- Semi-synthetic drugs with resistance to penicillinase. They are used to treat a wide range of pathogens. Representatives: methicillin, oxacillin, nafcillin.
- Carboxypenicillins (carbpenicillin).
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Group of broad-spectrum drugs:
- ureidopenicillins;-amidopenicillins.
Biosynthetic Forms
For example, it is worth giving some of the most common medicines at the moment that correspond to this group. Probably the most famous of the pennicillins can be considered "Bicillin-3" and "Bicillin-5". They pioneered a group of natural antibiotics and were the flagships in their category until more advanced forms of antimicrobials came along.
- "Extencillin". Instructions for use states that it is a long-acting beta-lactam antibiotic. Indications for its use are exacerbations of rheumatic disease and diseases caused by treponema (syphilis, yaws and pinta). Available in powders. "Extencillin" instructions for use do not recommend combining with non-steroidal anti-inflammatory drugs (NVPS), since competitive interaction is possible. This may adversely affect the effectiveness of treatment.
- "Penicillin-V" belongs to the group of phenoxymethylpenicillins. It is used to treat infectious diseases of the ENT organs, skin and mucous membranes, gonorrhea, syphilis, tetanus. It is used as a preventive measure after surgery, to maintain remission in rheumatism, chorea, bacterial endocarditis.
- Antibiotic "Ospen" is an analogue ofprevious drug. It comes in the form of tablets or granules. It is not recommended to combine with NVPS and oral contraceptives. Often used in the treatment of childhood diseases.
Semi-synthetic forms
This group of drugs includes chemically modified antibiotics derived from molds.
- First on this list is "Amoxicillin". Instructions for use (price - about a hundred rubles) indicates that the drug has a wide spectrum of action and is used for bacterial infections of almost any localization. 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 s alt is prescribed when bacteria produce penicillinase. The drug is acid-resistant, it can be taken orally, it 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 as tablets or in vials as liquid for injection.
- The last representative of semi-synthetic penicillins is ampicillin trihydrate. Instructions for use (tablets) indicatesthat it has a wide spectrum of activity, 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), as the drug potentiates their action.
Solvent
Penicillins are sold in pharmacies as a 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 diagnoses: lobar and focal pneumonia, pleural empyema, sepsis and septicemia, septic endocarditis, meningitis, osteomyelitis. Bacterial tonsillitis, diphtheria, scarlet fever, anthrax, gonorrhea, syphilis, purulent skin infections fall into the field of action.
There are few contraindications to treatment with the penicillin group. First, the presence of hypersensitivity to the drug and its derivatives. Secondly, the established diagnosis of epilepsy, which does not make it possible to inject the drug into the spinal column. As for pregnancy and lactation, in this case, the expected benefits should significantly exceed the possible risks, because the placental barrier is permeable to penicillins. While taking medicationthe baby needs to be temporarily switched to another method of feeding, as the drug passes into the milk.
Side effects can occur on several levels at once.
From the side of the central nervous system, nausea, vomiting, excitability, 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 deaths have been reported. Due to the bactericidal action, candidiasis of the vagina and oral cavity is possible, as well as dysbacteriosis.
Features of use
With caution, it is necessary to prescribe to patients with impaired liver and kidney function, with established heart failure. It should not be recommended to use them for people prone to allergic reactions, as well as for those who are hypersensitive to cephalosporins.
If five days after the start of therapy, no changes in the patient's condition have occurred, then it is necessary to use penicillin analogs or replace the group of antibiotics. Simultaneously with the appointment, 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 the interruption of medication without good reason causes resistance of microorganisms. And to overcome it, you will need stronger drugs that cause severe side effects.
Analogues of penicillin have become indispensable in modern medicine. Although this is the earliest open group of antibiotics, it still remains relevant for the treatment of meningitis, gonorrhea and syphilis, has a broad enough spectrum of action and mild side effects to 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.
