Antibiotics

Question 1

Penicillins

Answer 1

Amoxicillin: moderate spectrum, bacteriolytic, beta lactam antibiotic; route IV/oral; use CAP (typical)/COPD exacerbations/bronchitis; active against gram negative and gram positive bacteria
Co-amoxiclav: amoxicillin is susceptible to degradation by beta lactamase - producing bacteria so can be combined with clavulanic acid (a beta lactamase inhibitor)

Question 2

Tetracyclines (doxycycline)

Answer 2

Tetracycline inhibits protein systhesis
Broad spectrum action gram positive and negative
Useful for atypical infections (mycoplasma legionella)
Oral route only
Side effects - GI upset/staining teeth/lupus/allergy/photosensitivity

Question 3

Quinolones

Answer 3

Ciprofloxacin, levofloxacin, moxifloxacin
Mechanism of Action: DNA fragmentation
Gram positive and negative coverage (and pseudomonas)
Route: IV/oral/inhaled (CF)
Side effects: GI upset, C difficile, tendonitis, liver upset, prolonged QTc and arrhythmia

Question 4

Macrolides

Answer 4

Erythromycin, clarithromycin
Commonly used in resp infection (atypical pneumonia)
Mechanism of action: protein synthesis inhibitors
Route: IV/PO
Gram positive/limited gram negative cover
Side effects: GI, allergy, liver abnormality, prolonged QTc and interactions