Antibiotics: Risks and Nursing Implications

Risks of Antibiotics for Viral Illnesses

• Antibiotics target bacterial infections by killing bacteria (bactericidal) or inhibiting bacterial growth (bacteriostatic).
• Viral infections like colds, flu, and COVID-19 lack the structures that antibiotics target, making them ineffective.

Risks of Misusing Antibiotics

• Overuse of antibiotics can lead to bacteria developing resistance, making infections harder to treat
• An example is MRSA (methicillin-resistant Staphylococcus aureus).
• Antibiotics disrupt normal microbiota, allowing pathogenic bacteria or fungi like C. difficile and Candida to overgrow, which increases superinfection risk.
• Adverse reactions include allergies such as anaphylaxis with penicillins, GI issues, and drug interactions.

Nursing Implications for Antibiotic Use

• Educate patients that antibiotics are ineffective against viruses.
• Emphasize symptom management like fluids, rest, and fever reducers for viral infections.
• Promote vaccination for preventable viral diseases.

Superinfection Risk & Management

• Superinfections occur when antibiotics eliminate normal microbiota, allowing opportunistic pathogens to overgrow.

Common Superinfections

• Clostridium difficile (C. diff) causes pseudomembranous colitis, with symptoms including watery diarrhea, abdominal pain, and fever
• Treatment involves oral vancomycin or fidaxomicin
• Nursing interventions include contact precautions and handwashing with soap, avoiding alcohol-based sanitizers
• Oral and Vaginal Candidiasis (Thrush, Yeast Infection) presents with white oral plaques, vaginal itching, and cottage cheese-like discharge
• Treatment options are nystatin swish/swallow (oral) or fluconazole (systemic)
• MRSA & VRE (Vancomycin-Resistant Enterococcus) are hospital-acquired resistant infections
• These require contact isolation and culture testing.

Nursing Considerations for Superinfections

• Use narrow-spectrum antibiotics when possible.
• Monitor for signs of superinfection, such as oral thrush, persistent diarrhea, and vaginal itching.
• Reinforce proper hygiene and infection control measures.

Cephalosporin Generations & Surgical Prophylaxis

• Cephalosporins weaken the bacterial cell wall and are classified by generations
• Each generation has increasing Gram-negative coverage and resistance to beta-lactamases
• 1st Gen: Cefazolin treats Gram-positive cocci such as Staph and Strep, which is used for surgical prophylaxis
• 2nd Gen: Cefuroxime is used for respiratory infections, increasing Gram-negative coverage
• 3rd Gen: Ceftriaxone treats meningitis and gonorrhea, crossing the BBB (blood brain barrier)
• 4th Gen: Cefepime is broad-spectrum, covering Pseudomonas
• 5th Gen: Ceftaroline covers MRSA
• Cefazolin (1st Gen) is given 30-60 minutes pre-op to prevent surgical site infections (SSI)
• Alternatives like clindamycin or vancomycin are used in penicillin-allergic patients.

Vancomycin: Adverse Effects & Monitoring

• Vancomycin treats MRSA, severe C. diff, and resistant infections
• Red Man Syndrome occurs because of rapid IV infusion causing flushing, hypotension, and rash
• The prevention is slow infusion over ≥60 minutes with antihistamine premedication
• Monitor creatinine and BUN for Nephrotoxicity.
• Ototoxicity presents as tinnitus and hearing loss, especially with aminoglycosides.
• Thrombophlebitis requires central lines for prolonged therapy.

Nursing Monitoring for Vancomycin

• Draw trough levels (10-20 mcg/mL) before the next dose.
• Infuse slowly over ≥1 hour to prevent Red Man Syndrome.
• Monitor kidney function, especially in elderly patients or those on nephrotoxic drugs.

Aminoglycoside Monitoring: Gentamicin Dosing & Peaks/Troughs

• Aminoglycosides like gentamicin are potent bactericidal antibiotics used for severe Gram-negative infections

Key Risks of Aminoglycosides

• Nephrotoxicity can cause acute kidney injury (AKI).
• Ototoxicity can cause irreversible hearing loss.
• Neuromuscular blockade can cause respiratory depression.

Dosing & Therapeutic Drug Monitoring for Aminoglycosides

• Peak levels (highest concentration) should be measured 30-60 min after IV dose.
• Trough levels (lowest concentration) should be measured right before the next dose.
• Goal levels: Peak (5-10 mcg/mL), Trough (<2 mcg/mL).

Nursing Implications for Aminoglycosides

• Monitor BUN/creatinine for kidney function.
• Check for hearing loss like tinnitus and dizziness.
• Ensure hydration to reduce nephrotoxicity.

Tuberculosis (TB) Testing & Rifampin

• Tuberculin Skin Test (TST) & Diagnosis
• PPD Test (Mantoux test) should be read 48-72 hours after administration.
• Positive result based on size:

• 5mm: HIV+, immunosuppressed

• 10mm: Healthcare workers, high-risk populations

• 15mm: No risk factors

Confirming Active TB

• Chest X-ray is performed if the TST is positive.
• Sputum culture is the gold standard for active TB.

Rifampin Side Effects & Patient Education

• Hepatotoxicity should be monitored by watching ALT/AST.
• Red-orange body fluids are harmless, but stain clothes or contact lenses.
• Drug Interactions induce CYP450, reducing the effectiveness of warfarin and oral contraceptives.

Nursing Considerations for Rifampin

• Educate on adherence (DOT therapy is often used).
• Monitor liver function.
• Warn about urine discoloration.

Fluoroquinolones: Rare Adverse Effect

• Fluoroquinolones such as ciprofloxacin and levofloxacin are broad-spectrum antibiotics with strong Gram-negative coverage.
• A rare but serious side effect is tendon rupture (Achilles tendon).
• Risk factors include elderly patients, steroid use, and heavy exercise.
• Nurses should advise high-risk patients avoid this if pain or swelling occurs.
• Other key adverse effects include QT prolongation (avoid in cardiac patients) and photosensitivity (use sunscreen).

STI Drugs: Syphilis Stages & Treatment

• Treponema pallidum (Syphilis) Progression:
• Primary Syphilis presents as a painless chancre (ulcer) at the infection site
• Secondary Syphilis causes rash on palms/soles and flu-like symptoms
• Latent Syphilis is asymptomatic but still infectious
• Tertiary Syphilis results in neurosyphilis and cardiovascular complications.

Syphilis Treatment

• Penicillin G (IM injection) is the treatment of choice.
• If allergic, use doxycycline or tetracycline, but not in pregnancy.

Final Thoughts for Exam Preparation

• The key is to know drug mechanisms and indications
• Recognize adverse effects and patient safety concerns
• Understand key monitoring parameters for labs/dosing
• Be prepared for case-based scenarios, such as penicillin allergy management and TB testing interpretation

Know Drug Mechanisms & Indications

• Drugs work through a mechanism of action, MOA, and their clinical indications are critical to safe and effective nursing practice

Key Drug MOAs & Indications to Focus On

• Penicillins & Cephalosporins (Beta-lactams):
• MOA: Inhibit bacterial cell wall synthesis, causing bacterial lysis
• Indications: Streptococcal infections, syphilis (Penicillin G), surgical prophylaxis (Cefazolin)
• Key Concern: Allergy risk (assess for past reactions).
• Vancomycin:
  • MOA: Inhibits bacterial cell wall synthesis, but not a beta-lactam
  • Indications treat MRSA and severe C. diff (oral vancomycin)
  • Key Concern: Red Man Syndrome (slow infusion), nephrotoxicity, and ototoxicity.
• Aminoglycosides (Gentamicin):
  • MOA: Inhibits bacterial protein synthesis (bactericidal)
  • Indications treat severe Gram-negative infections
  • Key Concern: Nephrotoxicity and ototoxicity (monitor peaks/troughs)
• Tetracyclines (Doxycycline):
  • MOA: Inhibits bacterial protein synthesis (bacteriostatic)
  • Indications: Acne, Lyme disease, and chlamydia
  • Key Concern: Avoid use during pregnancy and in kids <8 (tooth discoloration) and be aware of photosensitivity.