Drug Classes Flashcards
B-lactams: MOA
Structural analogs of D-Ala-D-Ala
Covalently bind to PBPs to prevent cross linking, inhibit transpeptidation reaction (last step in peptidoglycan synthesis)
Bacterial resistance:
gram negative (can’t reach site of action)
Inactivation by B-lactamases
Structural differences in PBP
Penicillins: class, MOA
B-lactam
Inhibit cell wall synthesis
Natural Penicillins: spectrum, ADRs
Gram positive cocci (however, easily hydrolyzed by penicillinase)
Hypersensitivities: anaphylaxis, interstitial nephritis
Large dose: N/V/D, pseudomembranous colitis
Anti-Staphylococcal Penicillins: Spectrum, MOA
DOC for S. aureus, S. epidermis (not MRSA)
Penicillinase resistant
Hypersensitivities: anaphylaxis, interstitial nephritis
Large doses: N/V/D, pseudomembranous colitis
B-lactams: sub classes
Penicillins
Cephalosporins
Monobactams
Carbapenems
Aminopenicillins: Spectrum, ADRs, important drugs
Extended spectrum, frequently used with a B-lactamase inhibitor to reach gram negative, in addition to gram positive.
Hypersensitivities: anaphylaxis, interstitial nephritis
Large dose: N/V/D, pseudomembranous colitis
Ampicillin (+/- sulbactam)
Amoxicillin (+/- clavulanic acid)
Anti-Pseudomonal Penicillins: Spectrum, ADRs, important drugs
extends to P. aeruginosa, Enterobacter, anaerobes; can be used for serious gram negative infections (ie HAP, immunocompromised, etc.)
Hypersensitivities: anaphylaxis, interstitial nephritis
Large dose: N/V/D, pseudomembranous colitis
Piperacillin
Cephalosporins: MOA, resistance, ADRs
B-lactam, so same general MOA/ resistance as Penicillins
None have coverage with MRSA/MR- Listeria/Enterococci
1% risk of cross-reactivity with penicillins (esp when pt has true hypersensitivity) diarrhea, intolerance to alcohol
First Generation Cephalosporins: Spectrum, uses
Good gram positive coverage, modest gram negative coverage, oral anaerobes
Skin and soft tissue infections (SSTIs), surgical prophylaxis
Second Generation Cephalosporins: Spectrum
still good gram positive coverage, somewhat increased gram negative coverage
Third Generation Cephalosporins: Spectrum, uses, important drugs, ADRs
Less active against gram positive, better with gram negative, good coverage with Enterobacteriacea
DOC for serious gram negative infections (Klebsiella, Proteus, Serratia, Haemophilus)
Ceftriaxone
Ceftazidime
1% cross reactivity with penicillins; diarrhea; intolerance to alcohol
Fourth Generation Cephalosporins: Spectrum, uses, important drugs, ADRs
similar spectrum to third generation cephalosporins (prototype is resistant to many B-lactamases, excellent penetration to CSF)
EMPIRICAL TREATMENT OF NOSOCOMIAL INFECTIONS; serious infections in hospitalized patients (P. aeruginosa, Enterobacteriacae, S. aureus, S. pneumoniae)
Cefepime
1% cross reactivity with penicillins; diarrhea, intolerance to alcohol
Carbapenems: MOA, resistance, important drugs, spectrum, ADRs
B-lactam, so similar MOA and resistance to penicillins
Meropenem
Ertapenem
aerobic and anaerobic gram positive; excellent activity against Enterobacteriacae, Pseudomonas, Acinetobacter;
lower respiratory infections, abdominal/gynecological/ bone and joint
N/V; seizures; hypersensitivity
Monobactams: MOA, resistance, spectrum, use
B-lactam, so same MOA and resistance as penicillins
aerobic gram negative coverage only (Enterobacteriacae, Pseudomonas, H. influenzae, gonococci)
Use in pts who are allergic to penicillins/cephalosporins
Glycopeptides: MOA, resistance, important drugs, spectrum, uses, ADRs
Inhibits cell wall synthesis: binds with D-Ala-D-Ala terminal
Alteration to terminal (no longer D-Ala-D-Ala), or abnormally thick cell wall (NOT active with gram negative)
Vancomycin
Broad gram positive coverage: S.aureus (including MRSA); S. epidermis (including MRSE); Streptococci; Bacillus; Corynebacterium, Actinomyces; CLostridium
ORALLY FOR C. DIFF; osteomyelitis, endocarditis, CNS infections, bacteremia
macular skin rash, chills, fever, “Red Man Syndrome” (extreme flushing) due to rapid infusion; tachycardia, HTN
*Vancomycin has a direct effect on mast cells, causes them to release histamine
Fluoroquinolones: MOA, resistance, important drugs, spectrum, uses, ADRs
Concentration-dependent killing, targets bacterial DNA gyrase and topoisomerase (allows positive coiling of bacterial DNA)
Mutations in gyrase/topoisomerase
Levofloxacin (“respiratory fluoroquinolone”)
H. influenzae, Moraxella, S. aureus, E.coli, Salmonella, Shigella, Enterobacter, Campylobacter, Neisseria, P. aeruginosa, S. aureus, atypicals, intracellular pathogens (Legionella, mycobacterium)
Levofloxacin, in particular, as a respiratory fluoroquinolone: Streptococcus pneumoniae
mild GI sx’s, mild CNS sx’s, rash, photosensitivity,
Achilles tendon rupture (contraindicated in children)
Aminoglycosides: MOA, resistance, important drugs, spectrum, uses, ADRs
concentration-dependent killing; binds 30s ribosomal subunit, disrupts protein synthesis
entry is electron/oxygen transport-dependent
AGs have a residual bacteriocidal effect (after MIC)
AG-metabolizing enzymes, impaired transport of drug into cell
Gentamicin
aerobic gram negative; limited against gram positive (but has synergistic bacteriocidal effects on gram positive when combined with a cell wall-active agent (B-lactam, Vancomycin)
When there is resistance to other agents, or pt is very ill; Gentamicin is active against Serratia; used in HAP, peritonitis in peritoneal dialysis, synergistic in bacterial endocarditis
Ototoxicity (up to 25%), nephrotoxicity, neuromuscular block, apnea
Tetracyclines/Glycylcyclines: MOA, resistance, important drugs, spectrum, uses, ADRs
Bacteriostatic; binds to 30 s ribosomal subunit, blocks acceptor (A) site on mRNA (prevents addition of aa’s to growing peptide)
Decreased drug influx, energy-dependent efflux, ribosomal protection proteins, enzymatic inactivation
