Antibacterials Pharmacology Practice Flashcards

A complete set of vocabulary flashcards covering drug classes, generic/brand names, mechanisms of action, adverse effects, and clinical nursing considerations for antibacterials based on the Pharmacology Fall 2026 lecture.

Penicillin: Examples

penicillin G procaine (Wycillin), amoxicillin (Amoxil), dicloxacillin sodium (Dynapen), and Piperacillin-tazobactam (Zosyn).

Penicillin: Mode of Action

Beta-lactam antibiotics that bind penicillin-binding proteins (PBPs) to inhibit peptidoglycan cross-linking and bacterial cell-wall synthesis; they are bactericidal.

Penicillin: Adverse Effects

Common effects include GI upset and rash; serious risks include hypersensitivity (anaphylaxis), superinfection (C. difficile), and neurotoxicity/seizures with high concentrations.

Probenecid Interaction

Can increase penicillin concentrations by reducing renal tubular secretion.

Cephalosporin: Examples

cefadroxil (Duricef), cefazolin sodium (Ancef), cephalexin (Keflex), and cefdinir (Omnicef).

Cephalosporin: Mode of Action

Beta-lactam antibiotics that bind penicillin-binding proteins (PBPs) and inhibit bacterial cell-wall synthesis; they are bactericidal.

Cephalosporin: Precautions

A history of penicillin allergy does not automatically prohibit use, but prior reactions must be evaluated; renal dose adjustment is often required.

Macrolide: Examples

azithromycin (Zithromax), clarithromycin (Biaxin), and erythromycin base (E-Mycin).

Macrolide: Mode of Action

Binds primarily to the bacterial 50S ribosomal subunit for inhibition of protein synthesis; usually bacteriostatic.

Macrolide: Adverse Effects

GI upset, QT prolongation/arrhythmia risk, hepatotoxicity, and reversible hearing impairment (especially with high exposure).

Macrolide: Drug Interactions

Clarithromycin and erythromycin inhibit CYP3A4; azithromycin generally has fewer CYP-mediated interactions.

Tetracycline: Examples

tetracycline (Sumycin), doxycycline (Vibramycin), and minocycline (Minocin).

Tetracycline: Mode of Action

Binds to the bacterial 30S ribosomal subunit to prevent aminoacyl-tRNA attachment and inhibit protein synthesis; primarily bacteriostatic.

Tetracycline: Specific Adverse Effects

Photosensitivity, tooth discoloration, effects on developing bone/teeth, and esophagitis.

Tetracycline: Chelation Interaction

Aluminum, magnesium, calcium, iron, bismuth, and sucralfate can chelate these drugs and reduce absorption.

Aminoglycosides: Examples

amikacin sulfate (Amiken), gentamicin sulfate, and streptomycin sulfate (Streptomycin).

Aminoglycosides: Mode of Action

Irreversibly binds to the 30S ribosomal subunit causing mRNA misreading and inhibiting protein synthesis; shows concentration-dependent bactericidal activity.

Aminoglycosides: Major Toxicities

Nephrotoxicity and Ototoxicity (cochlear or vestibular damage); neuromuscular blockade is a rare but potentially serious risk.

Fluoroquinolones: Examples

ciprofloxacin (Cipro), levofloxacin (Levaquin), and moxifloxacin (Avelox).

Fluoroquinolones: Mode of Action

Bactericidal agents that inhibit bacterial DNA gyrase (topoisomerase II) and topoisomerase IV to block DNA replication and transcription.

Fluoroquinolones: Black Box Warnings/Risks

Tendinitis, tendon rupture, peripheral neuropathy, and CNS effects; may also cause QT prolongation and dysglycemia.

Sulfonamides: Examples

trimethoprim–sulfamethoxazole (TMP-SMX; Bactrim) and sulfadiazine.

Sulfonamides: Mode of Action

Sulfamethoxazole competes with PABA to inhibit dihydrofolic acid synthesis; trimethoprim inhibits dihydrofolate reductase; together they block folate metabolism.

Sulfonamides: Adverse Effects

Rash, photosensitivity, hyperkalemia (due to trimethoprim), bone-marrow suppression, and rare severe cutaneous reactions like SJS/TEN.

Metronidazole (Flagyl): Mode of Action

Reduced within anaerobic organisms to reactive intermediates that damage DNA and inhibit nucleic-acid synthesis; bactericidal.

Metronidazole (Flagyl): Patient Education

Adverse effects include a metallic taste and dark/reddish-brown urine; alcohol should be avoided during therapy and for 3 days after the last dose.

Linezolid (Oxazolidinone)

Used for resistant gram-positive infections (MRSA, VRE); inhibits the 50S ribosomal subunit to prevent the initiation complex; carries a risk of serotonin syndrome.

Clindamycin (Lincosamide)

Bacteriostatic agent binding the 50S ribosomal subunit; notably associated with C. difficile–associated diarrhea/colitis.

Vancomycin (Glycopeptide)

Bactericidal agent that binds D-Ala-D-Ala precursors to inhibit cell-wall synthesis; used for MRSA and orally for C. difficile.

Daptomycin (Lipopeptide)

Bactericidal drug that inserts into the bacterial membrane causing rapid depolarization; used for MRSA bacteremia but NOT for pneumonia due to surfactant inactivation.

Polymyxins

Used for multidrug-resistant (MDR) Gram-negative infections; they bind LPS and puncture the bacterial membrane; require renal function monitoring.

Amphotericin B

A polyene antifungal considered the gold standard for severe systemic fungal infections; creates pores in the membrane; requires monitoring of kidney function and electrolytes.

Gram Stain Impact on Drug Reach

Gram-positive bacteria have thick peptidoglycan for easy membrane access; Gram-negative bacteria have an outer membrane with LPS acting as an additional barrier.