Antibiotics and Resistance: Rules for Effective Treatment of Bacterial Infections

Introduction: The Challenge of Antibiotic Resistance

Bacterial infections remain one of the primary threats to human health, and antibiotics are the cornerstone of their treatment. However, the excessive and improper use of these vital drugs has led to a global problem: the rise of antibiotic resistance. Bacteria are becoming resistant to drugs, making the treatment of many infections extremely difficult and sometimes impossible [3, 8]. Understanding the principles of rational antibiotic therapy is critically important for both physicians and patients to preserve the efficacy of these drugs for future generations.

Why Antibiotics Lose Efficacy: The Threat of Resistance

Antibiotic resistance is a natural evolutionary process in which bacteria develop the ability to survive in the presence of antibiotics. However, this process is significantly accelerated by the irrational use of antibiotics. Key factors include:

• Over-prescription: Using antibiotics for viral infections, against which they are ineffective, or for treating colonizing bacteria that do not cause an active infection (e.g., in the respiratory tract or urinary catheters) [1].
• Incorrect drug selection: Choosing a broad-spectrum antibiotic when a more narrow-spectrum one would suffice, or failing to account for local epidemiology and the prevalence of multidrug-resistant organisms (MDROs) [1, 7].
• Inadequate doses and duration: Doses that are too low or treatment courses that are too short fail to eliminate all bacteria, allowing the most resistant ones to survive and multiply [1].

The spread of MDROs, especially in hospital settings, poses a serious threat, complicating the choice of effective therapy and increasing mortality [6, 8].

Basic Principles of Rational Antibiotic Use

Strategies for optimizing antibiotic use (so-called "antibiotic stewardship") aim to minimize resistance while maintaining maximum treatment efficacy [1]. Here are the key recommendations:

1. Accurate Diagnosis and Assessment: Before starting antibiotic therapy, it is necessary to conduct a thorough assessment of the patient's condition and, if possible, collect samples for microbiological testing. This allows for the identification of the pathogen and the determination of its susceptibility to antibiotics [2, 7].

2. Selection of the Optimal Drug:

• When choosing empirical therapy (before receiving culture results), one should consider the prevalence of MDROs in the given region or medical facility, as well as the patient's history of previous infections and antibiotic therapy [1, 6, 7].
• Preference should be given to antibiotics with a low potential for developing resistance [1].
• The drug should have good penetration capacity into the suspected site of infection [2].

3. Dosage and Duration:

• The antibiotic should be prescribed at the highest possible dose that does not cause toxicity to ensure optimal concentration at the site of infection [1, 3, 6].
• The course of treatment should be as short as possible, but sufficient to completely eliminate the infection [1].

4. Daily Re-evaluation and De-escalation: Therapy should be reviewed daily. After identifying the pathogen and determining its susceptibility, it is necessary to switch from a broad-spectrum to a more narrow-spectrum antibiotic (de-escalation). This reduces the risk of developing resistance, decreases toxicity, and lowers costs [2, 3, 7].

5. Source Control: In some cases, such as bacteremia, the inability to eliminate the source of infection (e.g., an infected implant) can lead to the failure of even adequate antibiotic therapy [5].

Specifics of Antibiotic Therapy for Sepsis and Septic Shock

Sepsis and septic shock are life-threatening conditions that require the immediate initiation of antibiotic therapy. Every minute of delay increases the risk of an adverse outcome [2, 8].

• Urgent Initiation: Intravenous antibiotics should be administered as soon as possible, ideally within the first hour after recognizing severe sepsis or septic shock [2, 7].
• Broad-Spectrum Coverage: Initial empirical therapy should be broad-spectrum, covering the most likely bacterial or fungal pathogens, with good penetration into the suspected site of infection [2, 3, 7].
• Combination Therapy: In cases of suspected multidrug-resistant organisms, infections caused by Pseudomonas, or in patients with neutropenia, combination antibiotic therapy is recommended. It expands the spectrum of activity and may be more effective [2, 5, 6, 7]. Combination treatment usually lasts 2-5 days, followed by de-escalation [6].
• Pharmacokinetics and Pharmacodynamics: In patients with sepsis, physiological changes can significantly affect how drugs behave in the body. Therefore, it is important to adapt the dosage, often starting with a high loading dose [3, 6, 7].
• MRSA Infections: Bacteremia caused by methicillin-resistant Staphylococcus aureus (MRSA) has a high mortality rate. If initial vancomycin therapy is ineffective, "salvage" therapy may be required, often involving drug combinations (e.g., vancomycin with a beta-lactam, daptomycin-containing regimens, or ceftaroline) [5].

Antibiotics for Children and Newborns: A Special Approach

Treating sepsis in newborns and children, especially in low- and middle-income countries, requires special attention. The World Health Organization (WHO) has developed guidelines that are constantly updated to account for growing resistance [4].

• In 2005, hospitalization and prophylactic intramuscular or intravenous administration of ampicillin and gentamicin were recommended for suspected sepsis [4].
• In 2015, when hospital referral was not possible, recommendations included intramuscular gentamicin and oral amoxicillin [4].

Constant review of these guidelines is necessary to account for changing susceptibility patterns, costs, and side effect risks [4].

Conclusion: Everyone's Responsibility

Combating antibiotic resistance is a shared task. Adherence to the principles of rational antibiotic therapy, developed based on scientific evidence, is the key to preserving the efficacy of antibiotics. This includes correct selection, dosing, and duration of treatment, as well as constant monitoring and adaptation of therapy. Only through the joint efforts of healthcare workers and patients can we slow the spread of resistant bacteria and ensure effective treatment of infections in the future [7].

Sources

1. Antibiotic Stewardship: Strategies to Minimize Antibiotic Resistance While Maximizing Antibiotic Effectiveness. (Medical Clinics of North America, 2018)
2. Optimizing antimicrobial therapy in sepsis and septic shock. (Critical Care Clinics, 2009)
3. Bench-to-bedside review: Appropriate antibiotic therapy in severe sepsis and septic shock--does the dose matter? (Critical Care (London, England), 2009)
4. Reviewing the WHO guidelines for antibiotic use for sepsis in neonates and children. (Paediatrics and International Child Health, 2018)
5. When sepsis persists: a review of MRSA bacteraemia salvage therapy. (Journal of Antimicrobial Chemotherapy, 2016)
6. Treatment of bloodstream infections in ICUs. (BMC Infectious Diseases, 2014)
7. Antibiotic therapy in patients with septic shock. (European Journal of Anaesthesiology, 2011)
8. Bloodstream infections in the Intensive Care Unit. (Virulence, 2016)

The information provided in this article is for reference purposes only and cannot replace professional medical advice. Always consult a qualified physician for the diagnosis and treatment of any medical conditions.