Penicillins Flashcards
*For what conditions is bactericidal antibiotic therapy required? (4 dz’s)
- Meningitis - Endocarditis - Osteomyelitis - Febrile neutropenia
Bactericidal or bacteriostatic? Cell wall formation/synthesis inhibitors are in general _____________. Nucleic acid synthesis inhibitors are ___________. Protein synthesis inhibitors tend to be ____________. Metabolic inhibitors are usually ______________.
Cell wall formation/synthesis inhibitors are in general bacteriocidal. Nucleic acid synthesis inhibitors are bacteriocidal. (exception: aminoglycosides) Protein synthesis inhibitors tend to be bacteriostatic. Metabolic inhibitors are usually bacteriocidal.
What are the 3 key concepts to consider regarding infection when considering antibiotic tx?
- Severity - Site - Organism
What are the 6 key concepts to consider regarding the host when considering antibiotic tx?
- Allergies - Age - Pregnancy - Renal/hepatic function - Drug interactions (w/theirs) - Underlying disease
What are the 7 key concepts to consider regarding the drug when considering antibiotic tx?
- Predicted activity/measured susceptibility - Clinical efficacy - “Drug of choice” - PK and tissue penetration - PD (need cidal?) - Side Effects - Cost
What are the 2 groups of natural PCNs?
PCN G and PCN VK (oral)
What are the 4 types of penicillinase-resistant penicillins?
Nafcillin, oxacillin, methacillin, dicloxacillin
What are the 2 aminopenecillins?
Ampicillin and amoxicillin
What is the name of the carboxypenicillin?
Ticarcillin (not avail.)
What is the name of the ureidopenicillin?
Piperacillin
Name 4 beta-lactamase inhibitor-combo treatments. (just the overall drug names)
- Unasyn - Timentin - Zosyn - Augmentin
Are PCNs time- or conc-dependent killing?
- Time-dependent
What group does PCNs have synergy w/?
Aminoglycosides (against Enterococcus spp., Staphylococcus spp., viridans strep, and gram-negative bacteria)
PCNs distribute throughout body tissues/fluids except for these 3 sites:
Eye, prostate, and uninflammed CSF.
*What 5 things are natural PCNs commonly used for treating, besides the organisms previously mentioned? (extra stuff that’s on slides but not blue)
- Actinomyces - Bacillus anthracis (anthrax) - Endocarditis prophylaxis - Prevention of rheumatic fever
What type of infections (not organisms) are amino-PCNs used to treat?
- Respiratory tract infections - Pharyngitis - Sinusitis - Otitis media - Bronchitis - UTIs
Although not clinically available, what types of conditions do ticarcillin and pipercillin typically treat?
Hospital-acquired infections
The beta-Lactamase Inhibitor Combination treatment Augmentin is typically used to treat what sx?
Sinusitis, otitis media, upper and lower respiratory tract infections, human or animal bite wounds (similar to amino-PCNs)
The beta-Lactamase Inhibitor Combination treatments Unasyn, Zosyn, Timentin are typically used to treat what major types of infections?
- Polymicrobial infections - Empiric therapy for febrile neutropenia or hospital-acquired infections (Zosyn)
MoA of all beta-lactams? - Cidal or static?
Inhibit cell wall synthesis by binding and thus inhibiting PBPs. Inhibits final transpeptidation step of peptidoglycan synthesis. - Bactericidal
*Most beta-lactams are eliminated by the ___________. *What are the exceptions? (don’t forget cephalosporins)
Kidneys - Nafcillin, oxacillin, dicloxacillin (PRPs) - Ceftriaxone (cephalosporin) - Cefoperazone (cephalosporin)
What are the beta-lactam mechs of resistance? (Which is most important?)
Beta-lactamase enzymes (most important; cephalosporins are less susceptable), PBP alteration, decreased membrane penetration
2 eg’s of organisms that inhibit beta-lactams via beta-lactamase are:
- PRSP - MRSA
What 2 drugs are contained in Unasyn?
Ampicillin-sulbactam
What 2 drugs are contained in Timentin?
Ticarcillin-clavulanate
What 2 drugs are contained in Zosyn?
Piperacillin-tazobactam
What 2 drugs are contained in Augmentin?
Amoxicillin-clavulanate
What is the route of administration of PCN G, aqueous form? Benzathine salt form? Procaine form?
- Aqueous: IV - Benzathine: IM - Procaine: IM
What is the route of administration for PCN VK?
PO (acid stable)
Which of the 4 penicillinase-resistant penicillins can be given orally?
Dicloxacillin
Which of the amino-PCNs have better oral uptake?
Amoxicillin
Which of the 4 beta-lactamase inhibitor combo treatment drugs can be given orally?
Augmentin
How do drugs like sulbactam, clavulante, and tazobactam block bacteria from attacking PCNs, which are given together with these drugs?
Prevent beta-lactamase enzymes from working
With PCNs, do we want more time above MIC, or greater peak:MIC ratio?
More time above MIC (cuz time-dependent killing)
ALL penicillins have ________ elimination half-lives, and require (frequent/infrequent) dosing. - What are the 2 exceptions to this?
Short (
*Name the main target organisms of natural penicillins.
- Penicillin-susceptible S. pneumoniae - infections due to other streptococci - Neisseria meningitidis - Syphilis - Clostridium perfringens + tetani
*Name the main target organism of penicillinase-resistant PCNs (PRPs).
Infections due to MSSA such as skin and soft tissue infections
*Name the main target organisms of aminopenicillins.
- Enterococcal infections (often with an aminoglycoside) - Listeria monocytogenes
*Name the main target organisms of Carboxypenicillins and Ureidopenicillins.
- Empiric therapy for HA-infections - Infections due to Pseudomonas aeruginosa (esp piperacillin)
Adverse effects of PCNs?
- Hypersensitivity rxns (3-10%; cross-reactivity amongst all + some other beta-lactams) - Neurologic (seizures) (- Hematologic) (- GI) (- Interstitial nephritis)
What organisms do natural PCNs inhibit?
Gram +: PCN-susc. S. aureus (rare), *PCN-susc. S. pneumoniae, *group streptococci, viridans streptococci, enterococcus spp., bacillus spp. Gram -: *Neisseria spp., Pasteurella multocida. Anaerobes: above the diaphragm, *clostridium spp. Other: treponema pallidus (*syphilis; drug of choice)
What organisms do penicillinase-resistant penicillins inhibit?
Gram +: meth.-susc. S. aureus (*MSSA; target), group streptococci, viridans streptococci.
What organisms do aminopenicillins inhibit?
Gram +: pen. Susc. S. aureus (rare), pen. Susc. S. pneumoniae, group streptococci, viridans streptococci, *enterococcus spp., *listeria monocytogenes. *Gram -: Proteus mirabilis, some e coli, salmonella, shigella, beta-lactam h. influenzae.
What organisms do carboxypenicillins inhibit?
Gram +: “marginal” Gram -: Proteus mirabilis, some e coli, salmonella, shigella, beta-lactam h. influenzae, enterobacter spp., pseudomonas aeruginosa (target)
What organisms do ureidopenicillins inhibit? (Lots, maybe just name the 2 targets)
Gram +: Viridans strep, group strep, some enterococcus. Gram -: Proteus mirabilis, some e coli, salmonella, shigella, beta-lactam h. influenzae, enterobacter spp., *pseudomonas aeruginosa (target), serratia marcescens, some klebsiella spp. Anaerobes: faily good activity (target)
What organisms do beta-lactamase inhibitor-combos inhibit?
Gram +: S aureus (target; not MRSA). Gram -: H influenzae, e coli, proteus spp., klebsiella spp., Neisseria gonorrhea, moraella catarrhalis. Anaerobes (target): Bacterioids spp.
