Mechanisms of Drug Resistance

Key Concepts

• Drug Resistance: Refers to how the body becomes resistant to drugs, preventing them from reaching the target site.
• Antibiotic Resistance: Occurs when antibiotics do not penetrate the infection site effectively (e.g., lungs, bone abscesses).

Causes of Drug Resistance

• First Pass Effect: Limits active metabolites of drugs taken orally, reducing efficacy.
• Altered Targets: Resistance due to inappropriate antibiotic usage, such as:
  • Prescribing antibiotics for viral infections.
  • Not completing full antibiotic courses.

Strategies to Decrease Resistance

• Providers should prescribe antibiotics only when necessary.
• Nurses should educate patients on the importance of appropriate antibiotic usage.

Challenges in Antibiotic Prescription

• Patients demand immediate remedies, leading to unnecessary prescriptions.
• Providers need to effectively communicate the rationale for not prescribing antibiotics.

Types of Antimicrobial Drugs

Bactericidal vs. Bacteriostatic

• Bactericidal: Kills bacteria directly.
• Bacteriostatic: Inhibits bacterial growth.

Spectrum of Coverage

• Broad Spectrum: Active against multiple organisms (e.g., gram-positive, gram-negative, anaerobic).
• Narrow Spectrum: Targets specific organisms, guided by culture and sensitivity tests.

Principles of Antimicrobial Agents

Indications and Side Effects

• Administer drugs based on specific indications.
• Common side effects: gastrointestinal issues (nausea, vomiting, diarrhea).

Precautions

• Oral Contraceptives: Antibiotics can reduce their effectiveness. Advise additional contraceptive methods.
• Super Infections: Antibiotics can kill beneficial bacteria, increasing risk of secondary infections.

Contraindications

• Do not administer drugs if the patient has allergies or sensitivities to any antimicrobial drug class.

Nursing Considerations

Allergy Management

• Maintain an accurate allergy list.
• Assess the nature of allergic reactions (e.g., rash, shortness of breath).

Monitoring and Evaluation

• Monitor white blood cell (WBC) counts and symptomology for drug response.
• Follow culture and sensitivity (CNS) results to ensure appropriate antimicrobial treatment.
• Nurses should check lab results and update providers on the effectiveness of treatments.