True or False: The approval of anti-bacterial medications has steadily decreased due to bacteria being able to become resistant to the drug.
True
True or False: Penicillins are excreted in the urine unchanged.
True
All beta-lactam antibiotics share what common feature?
beta-lactam ring
The beta-lactam ring is critical for what?
antimicrobial activity
What is the overall target of beta-lactam antibiotics that is associated with stopping infections?
inhibition of synthesis of bacterial cell walls
Viruses that infect bacteria are known as what?
bacteriophages
List things that structurally the bacterial cell wall is necessary for:
- Maintaining the cell's characteristic shape
- Countering the effects of osmotic pressure
- Providing a rigid platform for surface appendages
- Providing attachment sites for bacteriophages
What is a latticed polymer consisting of linear chains of the altering aminosugars NAG and NAM?
Peptidoglycan
The 4-5 amino acid short chains attached to NAM in peptidoglycan can be enzymatically cross-linked by what?
transpeptidase
True or False: If transpeptidase does not cross-link the amino acid chains of NAM, then the cell wall is unsupported.
True
Transpeptidase hydrolyzes which portion of the 4-5 amino acid chain?
DA-DA
Which type of bacteria has a thick layer of peptidoglycan (cell wall is 50-100 molecules thick)?
Gram positive
Gram positive bacteria's site of action will be where?
outside of the peptidoglycan layer
Which type of bacteria has a thin layer of peptidoglycan?
Gram negative
Gram negative organisms contain a single sheet of peptidoglycan (PG). How does this affect stability?
Less stable (must less rigid)
The PG layer in gram negative bacteria is found in between what?
inner and outer plasma membranes
Where is the site of action for antibiotics used against gram negative bacterial infections?
Periplasmic space
Beta-lactam antibiotics will block what?
transpeptidase (from cross-linking the amino acid chains)
Once beta-lactam antibiotics block transpeptidase, water diffuses into the cell in the hypertonic environment leading to what?
cell lysis
Beta-lactam antibiotics bind to and inhibit transpeptidase enzymes as well as other targets all related to transpeptidase known as what?
Penicillin-Binding Proteins (PBPs)
True or False: PBPs are important for maintenance of shape and for cell division.
True
When PBP (transpeptidase) binds to beta-lactam antibiotics what kind of bond is formed?
covalent bond (this inactivates the PBP)
True or False: PBP has a higher affinity for the drug rather than DA-DA.
True
Bacteria not being susceptible to a specific drug is known as what?
Intrinsic resistance
What is a gram negative bacteria that does not have pores/channels and therefore a lot of antibiotics cannot reach the site of action?
Pseudomonas aeruginosa
What kind of resistance occurs via mutations or homologous recombination?
Acquired resistance
A PBP sensitive gene combining with a PBP resistant gene and forming a recombinant PBP resistant gene is an example of what?
homologous recombination
Which bacteria are resistant via the acqusition of additional high molecular weight PBPs with low affinity for beta-lactams from unknown species?
MRSA
What can readily transfer from bacteria to bacteria leading to resistance?
plasmid DNA
Resistance can stem from what in addition to plasmid DNA transfer?
Transfer by viral delivery
Why is it important for a patient to finish their entire antibiotic regimen?
So that resistance doesn't develop from viral transfer or plasmid DNA transfer
Resistance can also occur as a result of inpenetration or efflux of antibiotic drugs from the bacteria. This is especially important in which species?
gram negative (i.e. pseudomonas aeruginosa)
What in the presence of beta-lactam antibiotics leads to hydrolyzing of the antibiotic's structure and therefore making the antibiotic inactive?
Water (this is why antibiotics for children are not reconstituted until picked up)
True or False: The hydrolysis of beta-lactam antibiotics leading to their inactivation is increased at higher temperatures.
True (this is why a lot of beta-lactam antibiotics for children are refrigerated)
What specific gene is expressed on plasmids and is the number one leading cause of resistance in beta-lactam antibiotics?
beta-lactamase
Beta-lactamases are shed continuously in which bacteria?
gram positive
Beta-lactamase is secreted only into the periplasmic space between the inner and outer membranes in which bacteria?
gram negative (little loss of beta-lactamase = doesn't need to be resynthesized to high degrees)
True or False: Drugs without zones of inhibition means those drugs are resistant.
True
The main function of what is preventing the colonization by pathogens?
Normal flora
Which bacteria causes 90% of all abdominal anaerobe infections?
Bacteroides fragilis
Which bacteria is very prevalent among cystic fibrosis patients due to the CF patients not being able to clear their lungs and developing pneumonia?
Pseudomonas aeruginosa
What 3 bacterium species are important for removing the conj. from oral contraceptives?
- Clostridium perfringens
- Clostridium septicum
- Clostridium tetani
Individual patients who are compliant with their oral contraceptives have been shown to have decreases in plasma ethyl estradiol most notably with which antibiotics?
- PENs
- TETs
Which drugs ABSOLUTELY decrease OC effectiveness by inducing hepatic metabolism of estrogens?
- Rifamycins (i.e. Rifampin)
- Griseofulvin (anti-fungal)
- these increase the metabolism of estrogens
Penicillin G and Penicillin V are effective against what bacteria in general?
gram positive
Penicillin G and Penicillin V are effective against what gram positive bacteria specifically?
Streptococcus pyogenes
Which penicillins have a highly narrow spectrum?
Penicillinase-resistant penicillins
Penicillinase-resistant penicillins are especially effective against which specific bacteria?
- Staphylococcus aureus
- Staphylococcus epidermis
Which penicillins have a broader spectrum than Pen G/Pen V and can include coverage for some gram negative bacteria?
Aminopenicillins
Which penicillins have the broadest spectrum?
Anti-pseudomonal Penicillins
Anti-pseudomonal Penicillins are effective against which specific bacteria?
Pseudomonas aeruginosa
What is a main problem associated with Penicillin G?
Not absorbed well from GI
True or False: Ingestion of food with ANY penicillin alters absorption.
True
Which penicillin is the ether derivative of penicillin G and has greater oral bioavailability?
Penicillin V
Penicillin G/V cover most streptococcus species. List the most common species that Pen G/V covers:
- S. viridans
- S. pyogenes
- S. pneumoniae (many resistant)
S. viridians is most prevalent where in the body?
oral cavity (mouth)
S. viridans is most commonly associated with which specific infection?
Endocarditis (cardiac valve infection)
S. pyogenes is most commonly associated with which specific infection?
Strep throat
S. pneumoniae is most commonly associated with which particular infection?
Bacterial pneumonia
Besides streptococcus species, what are some other bacteria that are sensitive to Penicillin G/V?
- Listeria monocytogenes
- Borrelia burgdorferi
Is Listeria monocytogenes a gram positive or gram negative organism?
Gram +
Listeria monocytogenes is most commonly associated with what specific infection?
Listeriosis (from raw food)
Borrelia burgdorferi is most commonly associated with which specific infection?
Lyme disease
Streptococcal pharyngitis is caused by what bacteria?
S. pyogenes (strep throat, scarlet fever)
Which streptococcus sp. are associated with reduction of heme iron?
Alpha hemolysis
Which streptococcus sp. are associated with complete rupture of RBC?
Beta-hemolytic
True or False: Group A Streptococcus (GAS) and Group B Streptococcus (GBS) are beta-hemolytic.
True
What is a classical member of GAS?
S. pyogenes
S. pyogenes (strep throat) can progress to what particular infections?
- Rheumatic fever
- Scarlet fever
S. pyogenes most commonly causes what?
skin-soft tissue infections (SSTI)
S. pyogenes has a link to what?
OCD/PANDAS
What is a classical member of GBS?
S. agalactieae
S. agalactieae can lead to the development of what in neonates if present in the vaginal tract and left untreated?
meningitis (neonatal sepsis)
S. agalactieae can lead to the development of what in the elderly?
bacteremia
True or False: Pregnant women should have a GBS antigen test performed at 25-28 weeks.
True
If a woman possesses GBS in the vaginal tract, the infection should be treated throughout labor and delivery with what?
Pen
Which streptococcus species is associated with soft tissue and requires alternative therapies to treat?
Streptococcal cellulitis
Which streptococcus species is associated with a "flesh-eating" infection?
Necrotizing fascilitis (Streptococcal gangrene)
Which penicillins are resistant to hydrolysis from the beta-lactamase enzyme?
Semi-Synthetic Penicillinase-Resistant Penicillins
List some common Semi-Synthetic Penicillinase-Resistant Penicillins:
- Methicillin
- Oxacillin
- Nafcillin
- Dicloxacillin
- Cloxacillin
Semi-Synthetic Penicillinase-Resistant Penicillins are narrow spectrum agents used for what specific infections?
- S. aureus (MSSA)
- S. epidermidis (MSSE)
Any S. aureus that is resistant to the penicillin/cephalosporin agents is known as what?
MRSA
True or False: MRSA and MRSE express a high molecular weight PBP with very low affinity for beta-lactams.
True
What are the 2 categories that MRSA infections are divided into?
- HA-MRSA (secondary to hospitilization, surgery, long-term care, dialysis, invasive device, etc.)
- CA-MRSA
Community-associated MRSA (CA-MRSA) typically presents as what kind of infection?
skin, soft-tissue
Methicillin resistance is the result of the bacteria's acquisition of what gene?
mecA gene
S. aureus and MRSA organisms produce three types of toxin. What are these 3?
- cytotoxins
- pyrogenic toxin superantigens
- exfoliative toxins
When toxins are synthesized in S. aureus and MRSA infections, there is a host response involving the recruitment of what?
polymorphonuclear leukocytes
What component of methicillin's structure protects it from being degraded from beta-lactamase?
bulky methoxy side chains (protect the carbonyl from a beta-lactamase attack)
Methicillin has a narrow spectrum to which infection due to it's bulky groups allowing for binding of staphylococcus sp. PBPs only?
MSSA
True or False: Nafcillin is highly resistant to beta-lactamase.
True
What is the spectrum associated with Nafcillin (which infections are covered)?
- MSSA
- MSSE
List some common brand names of Nafcillin:
- Nafcil
- Unipen
- Nalpen
Which drugs are isoxazolyl penicillins?
- Oxacillin
- Cloxacillin
- Dicloxacillin
In regards to isoxazolyl penicillins, adding what groups to their structures increases their overall potency?
Chloro groups (Cl)
Which penicillins have a broader spectrum of activity and include some gram negative organisms?
Aminopenicillins
List some drugs that belong to the aminopenicillin class:
- ampicillin
- amoxicillin
True or False: Ampicillins have no resistance to beta lactamase.
True
True or False: An organism resistant to Pen G/V should be considered resistant to aminopenicillins.
True
What are some brand names of ampicillin?
- Omnipen
- Polycillin
What group on aminopenicillins increases their hydrophilicity and therefore can cause a penetration to gram negative pores?
NH2
Ampicillin has increased acid stability versus Pen G/V so therefore better oral absorption (30-50%). What happens to the unabsorbed drug?
Stays in the GI tract (causing GI upset)
True or False: Ampicillin is preferred as injection.
True
Ampicillin mimics how many amino acids?
3
What component on Amoxicillin contributes to 95-100% absorption and therefore less GI upset?
The addition of the OH group
What are some brand names of Amoxicillin?
- Amoxil
- Trimox
Amoxicillin has similar activity to ampicillin, but greater coverage with what bacteria?
H. pylori
Aminopenicillins (Ampicillin/Amoxicillin) can be used to treat which respiratory illnesses?
- sinusitis
- otitis media
- bronchitis
Aminopenicillins are effective in covering which bacteria that can cause respiratory infections?
- S. pyogenes
- S. pneumoniae
- H. influenzae
S. pneumoniae is covered especially well by which drug?
Amoxicillin
Aminopenicillins are used in the treatment of what specific infection that can be caused by gram negative bacteria?
UTI
What are some gram negative bacteria that can cause UTIs that are treated with aminopenicillins?
- E. Coli (80% of cases = MOST COMMON)
- Proteus mirabilis
What is a gram positive bacteria that can cause a UTI and be treated with aminopenicillins?
Enterococcus sp.
Aminopenicillins can also be used in the treatment of meningitis in combination with other classes. List some bacteria that cause meningitis that aminopenicillins are effective against:
- Listeria monocytogenes
- Streptococcus sp.
Is Listeria monocytogenes a gram positive or gram negative bacteria?
gram positive
Aminopenicillins have been shown to be effective in the treatment of Lyme disease. Which bacteria cause Lyme disease?
Borrelia burgdorferi and mayonii
Borrelia burgdorferi and mayonii are both gram positive or gram negative?
gram negative
Infection and inflammation of the middle ear is known as what?
Otitis media
What type of otitis media produces pus, fluid, and inflammation?
Acute
What type of otitis media is associated with fluid persisting in the ear, fluid escaping, and there is no sign of an active infection?
OM with effusion
Otitis media that persistently reoccurs is known as what?
Chronic OM
Otitis media can stem from primary upper airway infections, allergies, or common cold causing congestion and swelling of the what in the middle ear?
eustachian tube
What are the 2 main purposes of the eustachian tubes?
- Relieve Pressure
- Drainage
What are the most common microbial organisms that cause otitis media?
- Streptococcus pneumoniae
- Haemophilus influenzae
True or False: In approximately 66% of cases, otitis media infections resolve on their own within 72 hours and therefore a child might not need antibiotic therapy.
True
Which drug should be used to treat otitis media if it has not been given to a patient in the last 30 days?
Amoxicillin
If amoxicillin has been used within the last 30 days, or was ineffective for 2-3 days, which drug is given to treat otitis media?
Amox/clavulanate (Augmentin)
Clavulanate is a potent irreversible inhibitor of what?
beta-lactamase
Beta-lactamase inhibitors can be thought of as "suicide substrates". What does this mean?
These drugs give themselves up for the good of the rest (give the antibiotics greater activity)
What is another beta-lactamase inhibitor used with ampicillin?
Sulbactam
What is the brand name of ampicillin/sulbactam injection?
Unasyn
Which bacteria is very commonly associated with hospital devices (catheters, inplantable devices, etc.)?
Acinetobacter baumannii (Acinetobacter sp.)
Acinetobacter baumannii (Acinetobacter sp.) can be effectively treated with which antibiotic?
Ampicillin/sulbactam (Unasyn)
Which penicillins are the most broad spectrum in terms of treating infections?
Antipseudomonal penicillins
Antipseudomonal penicillins are unique penicillins, because the cover which particular infection?
pseudomonas aeruginosa
Antipseudomonal penicillins can be subdivided into what main 2 penicillin categories (based on their structure)?
- Carboxypenicillins
- Ureidopenicillins
Which drug is a carboxypenicillin?
Ticarcillin
What is the brand name of Ticarcillin?
Ticar
True or False: Carboxypenicillins and Ureidopenicillins are NOT sensitive to beta-lactamase.
False; ARE sensitive
Which drug is a ureidopenicillin?
Piperacillin
Piperacillin has unique coverage to what specific bacteria?
Bacteroides fragilis
Piperacillin can be used in combination with tazobactam. What is tazobactam?
Beta-lactamase inhibitor
What is the brand name of Piperacillin/tazobactam?
Zosyn
90% of abdominal anaerobic infections are caused by what?
Bacteroides fragilis
What is by far the most common adverse event associated with penicillins?
hypersensitivity
ALL penicillins are excreted renally. What is another side effect that could be expected based on this information?
Nephrotoxicity
Which penicillins can cause platelet dysfunction and therefore alter clotting?
Antipseudomonal penicillins
Penicillins or penicilloyls can attach to what in the body leading to an IgE mediated reaction?
Proteins (body recognizes as foreign)
True or False: It is important to clean counting trays after dispensing penicillins or cephalosporins due to the potential for sensitizing a patient to that drug.
True (sensitizing a patient could lead to an allergic reaction later)
Which drugs are derived from sewage and therefore will be very smelly when urinated out?
Cephalosporins
Which bacteria are cephalosporins inactive against?
- L - L. monocytogenes
- A - Atypical organisms (Mycoplasma pneumoniae; Chlamydia sp.)
- M - MRSA/MRSE
- Enterococci
Which cephalosporin is the exception when covering MRSA?
Ceftaroline
Which cephalosporins penetrate very well into the CSF and therefore are useful in the treatment of bacterial meningitis?
- cefuroxime (Duricef)
- cefotaxime (Claforan)
- ceftriaxone (Rocephin)
- cefepime (Maxipime)
- ceftizoxime (Cefizox)
1st generation cephalosporins have good activity against which bacteria?
gram positive
True or False: 1st generation cephalosporins have appropriate coverage against MRSA.
False; MSSA
1st generation cephalosporins have modest activity against gram negative bacteria that can cause UTIs. Name some of these bacteria:
- E. Coli
- K. pneumoniae
- P.mirabilis
List the 1st generation cephalosporins:
- Cephalexin
- Cefadroxil
- Cefazolin
What is the brand name of Cephalexin?
Keflex
What is the brand name of Cefadroxil?
Duricef
What is the brand name of Cefazolin?
Ancef
Which first generation cephalosporin is commonly used as prophylaxis of infection (especially in a surgical setting)?
Cefazolin (Ancef)
Which 1st generation cephalosporin has an amine group just like ampicillin?
Cephalexin (Keflex)
Which 1st generation cephalosporin has the amine and para hydroxyl group like amoxicillin?
Cefadroxil (Duricef)
The 2nd generation cephalosporins have somewhat increased gram negative activity. Particularly against which gram negative bacteria?
bacteroides fragilis
List the 2nd generation cephalosporins:
- Cefuroxime
- Cefuroxime Axetil
- Ceftoxitin
- Cefotetan
What functional group on 2nd generation cephalosporins decreases attack by beta-lactamases?
syn-oriented methoxyimino group
Which 2nd generation cephalosporins possess the syn-oriented methoxyimino group?
- Cefuroxime
- Cefuroxime Axetil
What are the brand names for cefuroxime?
- Kefurox
- Zinacef
What is the brand name of Cefuroxime Axetil?
Ceftin
What is the brand name of Ceftoxitin?
Mefoxin
What is the brand name of Cefotetan?
Cefotan
Cefuroxime Axetil (Ceftin) is the prodrug of Cefuroxime. What does this allow for?
oral absorption
2nd generation cephalosporin penetrate into the CSF and are active against the 3 organisms that most commonly cause bacterial meningitis. What are these 3 organisms?
- H. influenzae
- N. meningitidis
- S. pneumoniae
Which cephalosporin is more active than any other ceph against anaerobes, especially bacteroides fragilis?
Cefotoxitin (Mefoxin)
Which cephalosporin has similar anaerobic activity to cefotoxin, good B. fragilis activity?
Cefotetan (Cefotan)
True or False: Cefoxitin (Mefoxin) and Cefotetan (Cefotan) possess the syn-oriented methoxyimino group in order to resist beta-lactamases.
False; do not possess (their increased steric bulk is what yields resistance to beta-lactamases)
3rd generation cephalosporins have similar activity against gram + cocci to the 1st generation and increase gram negative. However, 3rd generation cephalosporins are much more active against which bacteria?
Enterobacteriaceae
True or False: 3rd generation cephalosporins are resistant to common beta-lactamases.
True
Which 3rd generation cephalosporins are similar to cefuroxime in that they possesses a syn-methoxyimino group that protects it from beta-lactamases?
- Cefotaxime
- Ceftriaxone
What is the brand name of cefotaxime?
Claforan
What is the brand name of ceftriaxone?
Rocephin
What is the outstanding feature associated with ceftriaxone (Rocephin)?
Long half-life (8 1/2 hours)
Ceftriaxone (Rocephin) is often the agent of choice in the pen-sensitive treatment of what infection?
bacterial meningitis
What are the 3 main causitive organisms associated with bacterial meningitis?
- N. meningitis
- H. influenzae
- S. pneumoniae
The 3 main causitive organisms of bacterial meningitis (N. meningitis, H. influenzae, and S. pneumoniae) are normally present in which area of the body?
throat (back of the throat)
All 3 main causitive organisms of bacterial meningitis (N. meningitis, H. influenzae, and S. pneumoniae) are encapsulated by a what?
polysaccharide capsule (this allows them to invade immune system)
What part of the brain makes the CSF in which all 3 main causitive organisms of bacterial meningitis (N. meningitis, H. influenzae, and S. pneumoniae) can invade the ventricles of the brain leading to bacterial meningitis?
Choroid plexus
True or False: Bacterial meningitis is mainly an auto-inflammatory disease.
True
What are often the first symptoms associated with the presentation of bacterial meningitis?
- High fever
- Headache
- result from increased intracranial presssure
List some other symptoms associated with bacterial meningitis:
- fatigue
- vomiting
- altered mental status (i.e. confusion)
- intolerance to light
- stiff neck (from swollen/inflamed meninges)
- purpura (red dots/rashes around the body)
Which 3rd generation cephalosporins have the syn-directed protective groups to decrease beta-lactamase effects?
- Cefixime
- Cefdinir
- Cefpodoxime
What is the brand name of Cefixime?
Suprax
What is the brand name of cefidinir?
Omnicef
What is the brand name of cefpodoxime proxetil?
Vantin
Which 3rd generation cephalosporin chelates GI iron?
Cefdinir (Omnicef)
Due to Cefdinir (Omnicef) chelating GI iron, what is a major side effect?
feces will change color (red color)
True or False: Cefdinir (Omnicef) does not require refrigeration.
True
Which 3rd generation cephalosporin has a complex syn-side chain that offers it protection from chromosomal and plasmid beta-lactamases?
Ceftazidime
What is the brand name of ceftazidime?
Fortaz
Ceftazidime (Fortaz) has excellent activity against which bacteria?
pseudomonas
Which species of bacteria are anaerobic gram positive rods?
Clostridium
Which bacteria have spores that can form live bacteria if they are swallowed (the spores are resistant to acid and heat)?
C. difficile
C. difficile infections are associated with what?
antibiotic overuse (can occur with ANY antibiotic)
C. difficile infections lead to inflammation of the colon known as what?
pseudomembranous colitis
In C. difficile infections, what is the most common side effect?
severe diarrhea
C. difficile infections are highly associated with the use of which antibiotics?
Fluoroquinolones
True or False: The risk for C. difficile infections are increased with repeated antibiotic use and antibiotic combos.
True
The suppression of gastric acid production also increases the risk of C. difficile infections. List some drugs that are associated with gastric acid suppression and can increase the risk of C. difficile infections:
- H2-receptor antagonists (2x risk)
- PPIs (3x risk)
C. difficile infections are associated with toxins. What is the overall target of these toxins?
RhoGTPases
RhoGTPases are important for what?
actin polymerization (actin is important for normal GI functions)
Which enzyme on C. difficile toxins transfers a sugar onto RhoGTPases and inactivates the RhoGTPase and inhibits the production of actin?
Glucosyltransferase
In C. difficile infections, tight junctions in the GI tract are disrupted leading to increased permeability (water does not get absorbed appropriately). This leads to what main side effect in C. difficile infections?
diarrhea
What is the immediate approach to treating C. difficile infections?
discontinuing the offending antibiotic (20-25% of cases will resolve within 48-72 hours)
Why should antiperistaltic and opiate agents be avoided in C. difficile infections?
these drugs SLOW peristalsis and the toxin remains in the GI tract
What help to prevent alterations to the normal flora in the gut?
Probiotics (those kept cold are best = more viable cultures and need high culture concentration ~ 2 billion)
True or False: 4th generation cephalosporins can provide coverage to multiple resistant strains.
True
4th generation cephalosporins have excellent activity for which bacteria?
- streptococci
- MSSA
Which cephalosporin is a 4th generation?
Cefepime
What is the brand name of cefepime?
Maxipime
What hydrolyze the extended spectrum cephalosporins?
Extended Spectrum-beta-lactamases (ESBLs)
What are the viable options for treatment associated with ESBLs?
Carbapenems
5th generation cephalosporins have coverage for which infections?
- MRSA
- VRSA
- linezolid-resistant SA
True or False: 5th generation cephalosporins are NOT active against ESBL expressing bugs.
True
Do 5th generation cephalosporins cover pseudomonas?
No
Which drug is a 5th generation cephalosporin?
Ceftaroline Fosamil
What is the brand name of Ceftaroline Fosamil?
Teflaro
Which drug is a new generation cephalosporin that has excellent activity against P. aeruginosa?
Ceftolozane-Tazobactam
What is the brand name of Ceftolozane-Tazobactam?
Zerbaxa
Which drug is a cephalosporin siderophore approved for MDR (multi-drug resistant) gram negative cUTI?
Cefiderocol
True or False: There is a higher all cause mortality warning associated with Cifiderocol.
True
Cefiderocol has unique binding feature to what?
iron (can be brought into gram negative bacteria like pseudomonas due to iron uptake system)
True or False: Cefiderocol has no gram positive activity.
True
Which drugs are considered the broadest spectrum beta-lactams?
carbapenems
Imipenem is a carbapenem and is a component of which drug?
Primaxin
Due to cleavage in the kidney, Imipenem is dosed (1:1) with which drug to make Primaxin?
cilastain
What is the brand name of Imipenem/cilastatin + Relebactam?
Recarbio
Imipenem/cilastatin + Relebactam (Recarbio) is only used for which infections?
- cUTI
- cIAI
Most carbapenems cover everything but what?
MRSA
Which carbapenem has good coverage of acinetobacter?
Meropenem
What is the brand name of Meropenem?
Merrem IV
Meropenem + vaborbactam is indicated for what?
cUTI
Which carbapenem lacks good acinetobacter coverage?
Doripenem
What is the brand name of Doripenem?
Doribax
Which carbapenem is most potent?
Doripenem
Which carbapenem does not provide coverage to P. aeruginosa, Acinetobacter, and Enterococcus?
Ertapenem
What is the brand name of ertapenem?
Invanz
Any enterobacteriaceae can harbor resistance to carbapenems. What is this known as?
Carbapenem Resistant Enterobacteriaceae (CRE)
CRE is caused by bacteria possessing which enzyme?
Carbapenemase
Treatment for CRE is limited to which drugs?
- colistin
- tigecycline
- Avycaz
- plazomicin
- rifampin
What is the generic name for Avycaz?
Ceftazidime-Avibactam
True or False: Avycaz (Ceftazidime-Avibactam) is active against CRE, including KPC.
True
Which beta-lactam antibiotic is a monolactam?
Aztreonam
What is the brand name of aztreonam?
Azactam
Aztreonam (Azactam) is strictly efficient in treating what type of infections?
gram negative
Aztreonam (Azactam) shares a common R group with which medication?
Ceftazidime
True or False: A patient with an allergy to ceftazidime should NOT be given aztreonam.
True (cross-sensitivity rxn due to same R group)
Ampicillin shares the same R group as which cephalosporin (this cephalosporin should not be used due to a cross-sensitivity reaction if the reaction to ampicillin was severe)?
Cephalexin (Keflex)
Amoxicillin shares the same R group as which cephalosporin (this cephalosporin should not be used due to a cross-sensitivity reaction if the reaction to amoxicillin was severe)?
Cefadroxil (Duricef)
Which drugs belong to the lipoglycopeptide class?
- vancomycin
- telavancin
- dalbavancin
- oritavancin
What are the brand names associated with vancomycin?
- Vancocin
- Vancoled
True or False: Vancomycin is a very lipophilic drug.
False; hydrophilic
Due to vancomycin being very hydrophilic, this means what for the absorption of vancomycin?
poor oral absorption (virtually none)
Due to oral vancomycin having very poor absorption, it can be useful in treating which infection in particular?
C. difficile
Vancomycin is associated with which particular infusion reaction?
"Red Man Syndrome" (infusion MUST be slow to help avoid)
What is the side effect we are most concerned with in regards to Vancomycin?
nephrotoxicity (ototoxicity is also common)
Describe the MOA associated with Vancomycin:
Vancomycin forms 5 hydrogen bonds to the terminal DA-DA and inhibits transpeptidase from forming peptide backbone (cell wall does not form)
How do bacteria (i.e. Staphylococcus aureus) become resistant to Vancomycin (VRSA)?
mutate by changing the terminal amino acid sequence (not allowing vancomycin to form 5 hydrogen bonds to DA-DA)
The spectrum of Vancomycin is restricted to which kind of organisms?
Gram + (particularly gram + cocci)
Vancomycin is most associated in the treatment of what?
MRSA
True or False: Vancomycin can be useful in the treatment of multi-resistant strep.
True
Vancomycin can be used at higher concentrations in the treatment of bacterial meningitis. Why are higher concentrations needed?
to cross BBB
Telavancin is a vancomycin derivative. What is the brand name of telavancin?
Vibativ
Telavancin contains what unique structure?
lipophilic tail
True or False: Vancomycin is more potent compared to Telavancin.
False; Telavancin is more potent (2-8x)
What are the most commonly associated side effects associated with televancin?
- N/V/D
- taste disturbance
- foamy urine
Telavancin can interfere with what test?
coagulation (can make INR look off)
True or False: Telavancin can cause C. difficile associated diarrhea even though it is a treatment for C. difficile infections.
True
In addition to forming 5 hydrogen bonds with DA-DA like Vancomycin, what is an additional MOA of telavancin?
Lipid tail of Televancin will stick into bacterial membrane --> causing membrane depolarization and leakage of the membrane --> cell lysis
What are additional lipoglycopeptide antibiotics that share the same 2 MOAs with telavancin?
- Dalbavancin (Dalvance)
- Oritavancin (Orbactiv)
True or False: Dalbavancin (Dalvance) is most active against MSSA/MRSA and E. faecalis, but not VRE.
True
What is specifically unique about oritavancin (Orbactiv)?
10 day half-life (given as one-time dose over 3 hours)
Oritavancin (Orbactiv) precipitates in normal saline so it is administered via IV mixed with what?
D5W
Which drug uses Ca2+ to stick it’s tail through the membranes --> K+ leaks outside leading to depolarization of the membranes and lysis?
Daptomycin
What is the brand name of daptomycin?
Cubicin
Daptomycin (Cubicin) has only activity against which organisms?
gram positive
Uniquely daptomycin (Cubicin) has activity against enterococci species including what?
VRE
Daptomycin (Cubicin) is indicated for what?
right-sided endocarditis
Daptomycin (Cubicin) is inactivated to a good degree by what?
pulmonary surfactants in the lungs
Which agent is considered an agent of last resort and is effective/covers CRE?
Colistin(Polymxin E)/Colistimethate
Colistin(Polymxin E)/Colistimethate covers mostly what kinds of organisms?
gram negative
Colistin(Polymxin E)/Colistimethate is used as last resort due to the concern of what?
nephrotoxicity
Colistin(Polymxin E)/Colistimethate would be most associated with which infection?
VAP (Ventilator Associated Pneumonia)
Which antibiotics are considered broad-spectrum agents and are only used in topical formulations?
- Bacitracin A
- Polymyxin B
Which drug inhibits the bactoprenol transporter from allowing NAG and NAM to come outside of the cell (therefore inhibiting cell wall synthesis)?
Bacitracin A
The fatty acid portion of which drug dissolves in the hydrophobic region of the membrane and disrupts the membrane integrity?
Polymyxin B