Infectious Disease Antibiotics Review Spring 2025 PDF

Pharmacotherapy II: Antibiotics Augsburg PA Program, 2025 Mary Ruggeri, MEd, MMSc, PA-C  Examples: Examples: Trimethoprim / sulfamethoxazole (Bactrim) Pen G/Pen V Nafcillin Examples: Oxac...

Pharmacotherapy II: Antibiotics Augsburg PA Program, 2025 Mary Ruggeri, MEd, MMSc, PA-C  Examples: Examples: Trimethoprim / sulfamethoxazole (Bactrim) Pen G/Pen V Nafcillin Examples: Oxacillin Ciprofloxaci Ampicillin n Amoxicillin Levofloxacin Amox/Clauv Moxifloxacin Piperacillin Fluoroquinolone s Examples: TB 1st: drug Cephalexin Cefazolin Vanc 2nd: Topical Examples: Cefuroxime Azithromycin Cefoxitin Clarithromyci 3rd: n Ceftrixone Erythromycin Class: Cefotaxime Lincosamide Cefdinir s Class: Cefixime Ceftazidim Oxazolidinone e s 4th: Cefepime 5th: Examples: Ceftaroline Tetracycline, Doxycycline, Minocycline  Carbapenems MOA: Inhibit bacterial cell wall synthesis by binding to penicillin-binding proteins (PBPs) Broad-spectrum, bactericidal ⚬ serious bacterial infections, multidrug-resistant MO ⚬ Meropenem, Imipenem, Ertapenem, Doripenem ￭ Meropenem, Doripenem, Imipenem, - covers anaerobes, pseudomonas, gram neg & pos (not MRSA) ￭ Ertapenem - doesn’t cover pseudomonas ￭ Imipenem - not commonly used d/t increased risk of seizures AE: N/V/D, rash, seizures, cross-reactivity with PCN allergies, C.diff Interactions: reduce Valproic acid levels and increase seizure risk, renal clearance  Monobactams MOA: Inhibit bacterial cell wall synthesis by binding to penicillin-binding proteins (PBPs) ⚬ Aztreonam ￭ covers gram negative, pseudomonas ￭ alternative in patients with severe beta-lactam allergies (cross-reactivity is minimal) AE: N/V/D, injection site reaction; rare: hypersensitivity reactions, and potential liver enzyme elevations Cautions: impaired kidney function (renal clearance)  Aminoglycosides MOA: Binds to the 30S ribosomal subunit of bacteria, inhibiting protein synthesis. Bactericidal ⚬ Severe, gram negative infections (ex. sepsis, pneumonia, intra-abdominal) ⚬ Synergistic for Gram-pos infx (e.g., endocarditis) when combined with beta- lactams or vancomycin. ⚬ Gentamicin, Tobramycin, Amikacin, Streptomycin, Neomycin ￭ Gram negatives ￭ Gent & Tobra - pseudomonas AE: Ototoxicity (increased risk w/ loop diuretics - hearing loss, tinnitus, vertigo), Nephrotoxicity (inc risk with vanco or cephalosporins), Neuromuscular blockade ⚬ local: burning, irritation, corneal ulcer Cautions: impaired kidney function (renal clearance)  Linezolid Class: Oxazolidinone MOA: Inhibits bacterial protein synthesis by binding to the 23S ribosomal RNA of the 50S subunit. ⚬ Great bioavailability ⚬ Used for serious Gram-positive infections (complicated, HAP, etc) ⚬ Gram positives + MRSA, Vancomycin-resisetant Enterococci (VRE), Streptococci (including PCN resistant strains), limited gram neg and anaerobes ￭ Tedizolid (same class) - newer, less side effets, approved for skin/soft tissue infx AE: Serotonin syndrome, BM supprwsion and peripheral neuropathy, optic neuropathy (> 2wks use), thrombocytopenia Cautions: taking SSRI/SNRI, prolonged use, renal or hepatic impaired, preg/BF  Polymixins MOA: Disrupts bacterial cell membranes by interacting with phospholipids in the outer membrane, leading to leakage of cellular contents. ⚬ Polymyxin B and colistin (polymyxin E) ￭ Polymyxin B - also topical for ophthalmic and otic (bacterial conjunctivitis and bacterial otitis externa) and for skin infections ⚬ Bactericidal ⚬ Gram negatives, pseudomonas, klebsiella, acinetobacter baumanni ￭ reserved for multi-drug resistant gram negative infections (associated pneumonia, sepsis, complicated UTI) ￭ typically used as part of combination therapy AE: nephrotoxicity, neurotoxicity (dizzy, paresthesia, neuromuscular blockade) Cautions: renal impaired, neuromuscular disorders - only use when necessary d/t toxicity risks  Other 50S protein inhibitors Chloramphenicol ⚬ broad: gram pos, gram neg, anaerobes, some atypicals ⚬ not commonly used due to toxicity ￭ Typhoid fever (Salmonella typhi). ￭ Rickettsial infections (Rocky Mountain spotted fever) if no alternatives ￭ Severe infections in penicillin-allergic patients w/ no other options ￭ Topically as eye or ear drops ⚬ AE: BM suppression, aplastic anemia, gray baby syndrome Streptogramins ⚬ Quinupristin and Dalfopristin works synergistically ￭ Gram-positive aerobes, MRSA, VRE, Streptococcus pneumoniae, including PCN-resistant strains. ⚬ AE: musculoskeletal pain, infusion site reactions, hepatotoxicity, GI symptoms ⚬ Caution: liver impairment, with other drugs metabolized via CYP3A4 Review Games!