Martin D. Monroe

“β-lactams (penicillins, cephalosporins, carbapenems, monobactams)
Target the cell wall. Bactericidal. Time-dependent.
Best against Gram-positives (e.g. Strep, MSSA) and many Gram-negatives.
Common pitfall: underdosing in critically ill patients or skipping renal adjustment. Glycopeptides (vancomycin, teicoplanin)
Also hit the cell wall, but differently. Key for MRSA.
Slow bactericidal activity. Monitor levels, especially in renal impairment.
Not effective for Gram-negatives—too bulky to get through their outer membrane. Aminoglycosides (gentamicin, tobramycin, amikacin)
Target the ribosome → inhibit protein synthesis. Bactericidal.
Excellent against aerobic Gram-negatives, synergy with β-lactams for some Gram-positives.
Watch out for nephrotoxicity and ototoxicity. Use once-daily dosing unless contraindicated. Macrolides (azithromycin, clarithromycin)
Ribosome-targeting, but bacteriostatic.
Covers atypicals (e.g. Mycoplasma, Chlamydia), some Gram-positives.
Useful for community-acquired pneumonia and when penicillin allergy is an issue.”
― Martin D. Monroe, The Antibiotic Decision Handbook: 1000+ Clinical Exercises, Flashcards & QR Tools to Master Prescribing Antibiotics | Real Clinical Cases, Decision Moments & Checklists to Avoid Mistakes at Work