Since the discovery of penicillin by Alexander Fleming in 1920, antibiotics have become the main means of combating bacterial infections. Today it is thanks to them that it is possible to get rid of many diseases that were considered incurable a century ago and led to death. On the other hand, the uncontrolled and massive use of antibiotics stimulates the evolution of pathogens and their development of drug resistance. One of the possible ways out of this situation is rational antibiotic therapy. The principles of such therapy for various diseases are the topic of this article.
Fundamentals of Pharmacology
To begin with, we clarify that we call antibiotics substances of natural origin, which are characterized by pronounced biological activity. Over the past 50 years, scientists have discovered thousands of antibiotics that are obtained from bacteria, plants, animals directly and synthetically. In practice, we are dealing with a limited number of substances in connection with their various spectrum of action and the presence of side effects. The successes of molecular biology have revealed the mechanisms of antibiotic action on the bacterial cell and its membranes, made it possible to decipher the structure of these substances and put production on the rails of an industrial scale.
But if the development and introduction of the drug requires an average of 20 years, then pathogens can develop resistance to it in just a few years. And the emergence of strains of microorganisms resistant to existing drugs is scary.
Problem scale
Antibiotic resistance of pathogens today is one of the important social and medical problems. In a February 2017 report, the World Health Organization provided a list of 12 superbugs, the fight against which is considered a top priority. Their high resistance to antibiotics leads to an increase in their prevalence, serious consequences for the health of patients, and various levels of mortality. The principles of rational antibiotic therapy are one of the conditions for maintaining the sensitivity of pathogens to them.
Are bacteria well done?
I would like to say that the extreme ability to evolve among pathogens is to blame. But the great responsibility for increasing their overall antibiotic resistance lies with humanity.
Widespread production of such drugs reduced their cost, which is good. But it also led to their uncontrolled and irrational use, over-the-counter leave in pharmacies and the patient’s propensity to self-medicate led to the loss of a number of quite successful drugs by the pharmacology.
If the situation continues, humanity may be faced with a strain of the pathogen, in front of which we will be unarmed. That is why rational antibiotic therapy, the principles of which are aimed at the adequate use of drugs, becomes not desirable, but necessary.
Current requirements for antibiotics
These drugs have the following requirements:
- A high degree of activity against one or many (wide spectrum) types of pathogens.
- No toxicity to the human body.
- A wide therapeutic range: doses and concentrations should have a large scale of variation, while even a significant increase in drug concentrations should not be toxic.
- Good qualities in relation to accumulation in tissues to provide a therapeutic effect.
Obviously, in different clinical situations, antibiotics may not be equally rational. Some will be useful, others not. Some are dangerous, others are harmless. Some are economically justified, others are unacceptably costly.
Rational and adequate approach
For each nosology and individual patient, rational antibiotic therapy is different, but general directions can be formulated. The principles of rational antibiotic therapy include:
- Pharmaceutical - the appointment of drugs, taking into account expiration dates and compliance with storage standards.
- Based on microbiology, the principle of rational antibiotic therapy states that antibiotics are prescribed in accordance with the resistance of a particular pathogen to them.
- The clinical principle is the choice of an antibacterial agent, its dose, method of administration should include minimal damaging effects on the patient's body. And also take into account age, gender and associated pathologies.
- The epidemiological principle of rational antibiotic therapy takes into account the resistance of the pathogen to the environment that surrounds the patient (hospital, geographical region).
- The principle of adequate combination when using several drugs.
- The effectiveness of the antibiotic. If within 2-3 days there is no positive dynamics, the drug should be changed.
Rational antibiotic therapy in surgery
A feature of antibiotic therapy in surgical interventions is based on the prevention of infections after them. The essence of prevention in this case is to achieve an effective concentration of the antibiotic in the tissues before surgery, during surgery and within 3-4 hours after it. For surgery, the concept of antimicrobial prevention is based on the following principles:
- The probability of microbial contamination of the wound by the end of the operation is inevitably about 90%.
- An effective concentration of antibiotic in the tissues should be achieved before surgery.
- Continued administration of the drug after a day after surgery is ineffective.
Pneumonia: features of antibiotic therapy
Rational antibiotic therapy in pulmonology is associated with the complexity of determining the pathogen. The choice of antibiotic is carried out taking into account the category of the patient, in total there are four of them:
- Mild patients with community-acquired pneumonia. The causative agent with a high degree of probability is pneumococcus, chlamydia, mycoplasma.
- Community-acquired pneumonia in people over 60 years of age. In addition to previous pathogens, hemophilic bacilli and Staphylococcus aureus are very likely to appear.
- Severe pneumonia requiring hospitalization. Pathogens are approximately the same as in the previous group, but the patient's condition is moderate.
- Pneumonia characterized by a severe form of the course and requiring hospitalization of the patient in the intensive care unit. In this case, in addition to pneumococci and staphylococcus, the appearance of legionella and synergistic rods is quite likely.
Rational antibiotic therapy for pneumonia should take into account the whole complex of symptoms and the severity of the course of the disease.
Children are a special contingent
Rational antibiotic therapy in pediatrics is a complex issue in connection with the formation of natural immunity in the children's body. All the principles of antibiotic treatment for a pediatrician become very important. In this case, special attention is paid to starting antimicrobial therapy. In this case, the microbiological aspect and the identification of a specific pathogen become very important.
The rational choice of antibiotic and treatment protocol is determined by three main factors:
- Microbiology of the causative agent of the disease.
- The sensitivity of pathogens to antimicrobial agents.
- The distribution and spread of the antibiotic is precisely in the focus of inflammation (for example, in the bronchi or lung parenchyma).
In pediatricians, the choice most often falls on a broad-spectrum antibiotic with minimal therapeutic doses. In not severe conditions, preference is given to traditional antibiotics (Ampioks, Gentamitsin), which are taken orally. In severe situations, the pediatrician has no right to make a mistake and test various antibiotics, starting with not the strongest ones.
Summarize
The correct and rational use of antibacterial drugs is the key to effective disposal of the body from bacterial pathogens. Timely treatment will prevent the transition of the disease into a chronic form, when it becomes more difficult to pick up antibiotics.
And although public opinion has diametrically opposed points of view on the appropriateness and rationality of the use of antibiotics, the truth is somewhere between the extreme points.