Exam 2: Antimicrobial Families Flashcards
What are the 4 families of beta-lactams?
Penicillin
Cephalosporin
Carbapenem
Monobactam
What are the subcategories of Pencillin?
Narrow spectrum
Broad spectrum
Extended spectrum
Potentiated
What drugs are classified as narrow spectrum penicillins?
Penicillin G
Penicillinase-resistance penicillins
What drugs are classified as broad spectrum penicillins?
Ampicillin
Amoxicillin
Hetacillin
What drugs are classified as extended spectrum penicillins?
Piperaciliin
Ticarcillin
What drugs are classified as potentiated penicillins?
Clavamox (oral amoxicillin and clavulanic acid)
Unasyn (injectable ampicillin and sulbactam)
Timentin (injectable ticarcillin and clavulanic acid)
Zosyn (injectable piperacillin and tazobactam)
What are the subcategories of cephalosporin?
First generation
Second generation
Thrid generation
What drugs are classified as first generation cephalosporins?
Cephalothin
Cephalexin
Cefazolin (only injectable 1st generation)
Cephapirin
What drugs are classified as second generation cephalosporins?
Cefoxitin
Cefotetan
What drugs are classified as third generation cephalosporins?
Cefotaxime
Ceftriaxone
Ceftazidome
What drugs are classified as carbapenems?
Imipenem
Meropenam
What drug is classified as a monobactam?
Azotreonam
What are the adverse effects associated with Penicillin G?
Remarkably nontoxic
Do not use in Guinea pigs, hamsters, or rabbits
Primary adverse reactions are allergic
What are the adverse effects associated with Broad spectrum penicillins?
Large doses of ampicillin can cause diarrhea in horses
Disrupts flora if given orally to ruminants
Trihydrate form is too irritating for use in horses, causes sterile abscesses
What are the toxicities associated with Penicillin G?
Remarkably nontoxic in itself
Some toxicity is associated with accompanying salt or ester
What are the toxicities associated with beta-lactams?
Beta-lactams are chemically incompatible with aminoglycoside antibiotics and should not be combined in vitro
What is the public health concern associated with third generation cephalosporins?
3rd generation cephalosporins resistance due to extended-spectrum beta-lactamases
Are beta-lactams bacteriostatic or bactericidal?
Beta-lactams are bactericidal, though if treated in an environment isotonic to their cytoplasm, only a static action occurs
What are the pharmacodynamics of penicillin?
Time-dependent killing
What is the beta-lactam mechanism of action?
Work by inhibiting bacterial cell wall synthesis by binding to penicillin binding proteins (PBP)- the cross-linkage of the peptidoglycan cell wall cannot occur
How is penicillin G eliminated?
Renal filtration and secretion
How are ampicillin and amoxicillin eliminated?
Renal filtration and secretion
Which drugs have an intracellular, all tissue including CNS, distribution pattern? Which cross the BBB?
3rd generation injectable cephalosporin
3rd generation cephalosporins and carbapenems
Which drugs have an extracellular distribution pattern?
Majority of beta-lactams:
Penicillins primarily have extracellular distribution, but they can cross the BBB
Ampicillin and amoxicillin
Which antibiotic loses its activity in purulent debris?
Beta-lactams
Which drugs have a high probability of clinical success against staph?
Clavamox (most common) Timentin Cephalexin (most common) Cefazolin Cefoxitin Ceftriaxone Ceftazidime Ceftiofur Cefpodoxime Cefovecin Meropenem
Which drugs have a high probability of clinical success against strep?
Penicillin G Ampicillin and amoxicillin Ticarcillin and piperacillin Clavamox Timentin Cephalexin Cefazolin Cefoxitin Ceftriaxone Ceftazidime Ceftiofur Cefpodoxime Cefovecin Meropenem
Which drugs have a high probability of clinical success against E. coli?
Ticarcillin and piperacillin Timentin Cefazolin Cefoxitin Ceftriaxone Ceftazidime Ceftiofur Cefpodoxime Meropenem
Which drugs have a high probability of clinical success against Pasteurella?
Ampicillin and amoxicillin for small animals Ticarcillin and piperacillin Clavamox Timentin Cephalexin Cefazolin Cefoxitin Ceftriaxone Ceftazidime Ceftiofur Cefpodoxime Cefovecin Meropenem
Which drugs have a high probability of clinical success against obligate anaerobes?
Penicillin G Ampicillin and amoxicillin Ticarcillin and piperacillin Clavamox Timentin Cefoxitin Meropenem
Which drugs have a high probability of clinical success against Bacteroides fragilis?
Clavamox
Timentin
Cefoxitin
Meropenem
Which drugs have activity against Chlamydia?
Ampicillin and amoxicillin
Clavamox for cats
Which drugs have activity against Leptospira?
Penicillin G will put the animals in remission, but it will not remove the carrier state
Ampicillin and amoxicillin do the same as Penicillin G
Ticarcillin and piperacillin same as Penicillin G
Clavamox is the same as Penicillin G
Timentin is the same as Pen-G
Which drugs have activity against Pseudomonas?
Ticarcillin and piperacillin Timentin Ceftazidime Clavamox in cats Meropenem
Which drugs have activity against Lyme?
Ceftriaxone
Ceftazidime
Cefovecin
When either MRSA or MRSI is cultured, what does this imply regarding its susceptibility to all betalactams?
MRSA and MRSI are resistant to the entire beta-lactam family
How does cefazolin differ from other first-generation cephalosporins?
It is the only injectable and has better activity against E. coli
Which cephalosporins have reliable activity against obligate anaerobic gram-negative bacteria, include B. fragilis?
Cefoxitin and cefotetan
Which beta-lactams are inactivated by penicllinase?
Penicillin G
Which beta-lactams are inactivated by extended spectrum beta lactamase?
Third generation cephalosporins
Which beta-lactams are inactivated by carbapenemases?
Fourth generation cephalosporins
What are the obtained Cmax values and duration of therapeutic concentrations of crystalline penicillin G?
Rapid high concentrations
Short duration of plasma concentrations
What are the obtained Cmax values and duration of therapeutic concentrations of procaine penicillin G?
Lower concentrations, but prolonged duration compared to crystalline pen-G
What are the obtained Cmax values and duration of therapeutic concentrations of benzathene penicillin G?
Extremely low concentrations with prolonged duration
Qualitatively compare ampicillin sodium versus ampicillin trihydrate injections relative to obtained Cmax values and duration of therapeutic concentrations.
Sodium ampicillin has rapid absorption with rapid elimination, so typically given every 8 hours
Ampicillin trihydrate injections resemble procaine penicillin and it has lower concentrations used with longer absorption.
Which cephalosporin family is considered the drug of choice in treating gram-negative meningitis?
Third generation cephalosporins
What other beta-lactams cross the BBB sufficiently to treat a meningitis (without relying on inflammation to breakdown the BBB)?
Carbapenems penetrates BBB and inflammation enhances this penetration
Why are ampicillin trihydrate and amoxicillin trihydrate not recommended for use in horses?
Only the sodium form should be used in horses
The trihydrate form given to a horse can give them a sterile abscess
In general, horses do not handle IM injections well
What cephalosporin is effective against Pseudomonas?
Ceftazidime
Contrast the three ceftiofur formulations available as tradenames Naxcel, Excenel, and Excede.
Naxcel: cetiofur sodium
Excenel: cetiofur HCl
Excede: cetiofur crystalline free acid
Which antimicrobial is approved for parenteral use in dairy cattle that has no milk withdrawal and a short slaughter withdrawal?
Ceftiofur in all injectable forms
What beta-lactam family has the widest spectrum activity and the least likelihood of resistance?
Carbapenems
Describe the combination of an aminoglycoside with a beta-lactam
Can be synergistic relative to antimicrobial activity, yet a chemically incompatible when mixed in vitro
