08 Beta-Lactams Wong-Beringer Flashcards
What are the different classes of Beta-Lactams?
Penicillins. Cephalosporins. Monobactam. Carbapenems
What are the PCN derivatives used?
Penicillin (procaine). Ampicillin (amoxicillin). Oxacillin (dicloxacillin). Piperacillin
What is the 1st generation IV Cephalosporin?
Cefazolin
What are the 2nd generation IV Cephalosporins?
Cefuroxime. Cefoxitin. Cefotetan
What are the 3rd generation IV Cephalosporins?
Ceftazidime. Ceftriaxone. Cefotaxime
What is the 4th generation IV Cephalosporin?
Cefepime
What is the 5th generation IV Cephalosporin?
Ceftaroline
What is unique about Ceftaroline?
First Beta-Lactam with activity against MRSA
What are the different Carbapenems used?
DIME: Doripenem, Imipenem, Meropenem, Ertapenem
What are the “Natural” Penicillins?
Penicillin G or Pen VK. Narrow spectrum
What do the “Natural” Penicillins cover?
Gm (+) cocci (streptococci, enterococci, high rates of R with staph), Gm (+) bacilli, Gm (-) cocci (N. meningitidis (high rates of R w/ N. gonorrheae)), Spirochetes (Treponema). NOT Gm (-) bacilli
What is the DOC for Treponema?
“Natural” Penicillins
What are the therapeutic uses for “Natural” Penicillins?
DOC for infections due to susceptible bacteria. Rheumatic fever prophylaxis
What are the Penicillinase-Resistant Penicillins?
Oxacillin. Structure confers resistance to destruction by B-lactamases. Less active thatn Pen G against Gm (+) bacteria
What is Oxacillin used for?
“Narrow” - Anti STAPHYLOCOCCAL. “Natural” penicillins don’t cover this
What are the Aminopenicillins used?
Ampicillin, Amoxicillin. Broader spectrum than Pen G but not stable in the presence of B-lactamses. Combination with B-lactamase inhibitors restore activity against SOME B-lactamase producing strains
What do Aminopenicillins cover?
Gm (+) cocci: Strep, Enterococci (S. aureus (many R d/t B-lac+). Gm (+) bacilli: Listeria. Gm (-) cocci: Moraxella. Gm (-) bacilli. Anaerobes
How does Amoxicillin compare to Ampicillin?
More complete PO absorption and less frequent dosing than ampicillin
What are Aminopenicillins the DOC for?
Enterococcal infections, Group B streptococci, Listeria, Proteus mirabilis, and E. coli, H. influenzae
What prophylaxis is Amoxicillin used for?
Endocarditis prophylaxis for patients undergoing dental procedures
What is Amox/Clav acid (PO) used for?
URIs, LRIs, UTIs due to amox-resistant organisms
What is Augmentin?
Amox/Clav acid
What is Amp/Sulbactam (IV) used for?
Intraabdominal, gynecologic, skin and soft tissue infections
What is Unasyn?
Ampicillin/Sulbactam
What are the Carboxy- and Ureido- Penicillins?
Piperacillin (NOT stable in presence of B-lactamase)
What does Piperacillin cover?
Expanded Gm (-) spectrum: Pseudomonas, Klebsiella, Enterobacter, Citrobacter, Serratia. Gm (+) cocci: non-BL producing Staph, Strep, and Enterococci
What is Zosyn?
Piperacillin/Tazobactam - Restores piperacillin activity against some B-lactamase producing strains
What is Piperacillin the DOC for?
Serious Pseudomonas infections (use in combination with an aminoglycoside)
What is the therapeutic use of Zosyn?
Mixed infections: intraabdominal, gynecologic, skin and soft tissue
What is the absorption like for oral Pen V?
Easily destroyed by gastric acid (~1/3 is absorbed from the duodenum). Administer on an empty stomach (1 hour before meals or 2 hours after)
What is the PK of Pen G administered IM?
Slow release –> low but persistent levels of antibiotic in the blood (12 hours to several days or week). Procaine Penicililn, Benzathine Penicillin
What is IM Pen G often used for?
Syphilis and Rheumatic Fever
What is the main route in which PCN Derivatives are eliminated?
Renal clearance
Which PCN Derivatives DO NOT need to be renally adjusted?
Oxacillin, Nafcillin
What is the dosing schedule like for PCN Derivatives?
Multiple times per day
What are the Beta-Lactamase inhibitors used?
Clavulanic Acid ~ Tazobactam > Sulbactam
What are the characteristics of Beta-Lactamase Inhibitors?
Minimal direct antibacterial activity. Binds IRREVERSIBLY to B-lactamase –> prevent destruction of the B-lactam ring
What does the inhibitor activity of B-lactamase inhibitors depend on?
Type and amount of B-lactamase present. Compound to be protected. pH of the environment
What are the susceptible B-lactamase producing strains?
S. aureus, Bacteroides fragilis, Most strains of E. coli, Klebsiella pneumoniae
What strains are B-lactamase inhibitors NOT active against?
B-lactamases from Pseudomonas, Enterobacter, Serratia, Citrobacter
What are the Adverse Effects associated with PCN Derivatives?
Hypersensitivity Reactions (rash most common, cross-sensitivity among all penicillins, IgE-mediated immediate type: hives, laryngeal edema, anaphylaxis). GI: diarrhea. Superinfection with C. difficile. Bone marrow suppression
Which PCN Derivatives can cause electrolyte imbalance?
Ticar, high dose Pen VK
Which PCN Derivatives can cause seizures?
High dose Pen G, Imipenem. Higher risk in renal failure, elderly, CNS disorder
Which PCN Derivatives can cause thrombophlebitis?
Nafcillin
How are Cephalosporins classified?
Classification by generation: Chronology, Antimicrobial activity
What are the 1st generation PO Cephalosporins?
Cephalexin. Cephradine. Cefadroxil