ABXInfectiousdiseaseThroughABX3 Flashcards
1.††† What are the 5 actions of antimicrobial drugs?
Inhibits cell wall synthesis, inhibition of cell wall synthesis, inhibition of nucleic acid replication and transcription, injury to plasma membrane, inhibition of synthesis of essential metabolites
2.††† True or false: not all antibiotics elicit allergic responses
False, all ABX have the capability to elicit allergic responses. They range from annoying rashes to anaphylaxis and stevens-johnsons syndrome
3.††† What is stevens-johnsons syndrome
Often, Stevens-Johnson syndrome begins with flu-like symptoms, followed by a painful red or purplish rash that spreads and blisters. Then the top layer of the affected skin dies and sheds.
4.††† What agents target cell wall synthesis?
Beta-lactams, vancomyocins, daptomyosin, bacitracin
5.††† What agents act directly on the cell membrane of the microorganism affecting permeability and leading to leakage of intracellular compounds?
Detergents (polymixin)
6.††† What agents interfere with protein synthesis by interacting with bacterial ribosomes (6)?
Chloramphenicol, tetracyclines, macrolides, clindamysin, streptogramins, ketolides
7.††† What agents interfere with protein synthesis by blocking initiation?
Oxazolidinones (linezolid)
8.††† What agents interfere with protein synthesis by inhibiting tRNA synthesis?
Mupirocin
9.††† What agents interfere with protein synthesis through multiple mechanisms that lead to disruption of RNA processing?
Aminoglycosides
- What agents inhibit DNA processing by DNA topoisonerases?
Quinolones
- What agents inhibit DNA processing by directly inhibiting DNA-dependent RNA polymerase?
Rifampin
- What agents inhibit DNA processing by indirectly inhibiting DNA-dependent RNA polymerase?
Nitrofurantoin
- What agents act by blocking bacterial folic acid pathway (the antimetabolites)? 2
Trimethoprim and sulfonamides
- Antibiotics used in empiric therapy are called what?
Broad spectrum
- What is the goal of antibiotics used in definitive therapies?
To choose a therapy most selectively active for the organism, with the least potential for toxicity
- What organisms are covered with antibiotics?
Bacteria and fungus.
- Where does the problem lie in low immune responses with humoral immunity?
Inadequacy in the immunoglobulins
- Where does the problem lie in low immune responses with cellular immunity?
Inadequacy in phagocytic cells
- When are bactericidal agents more useful?
In patients with bacterial endocarditis or meningitis, in neutropenic patients, or those with a immunodeficiency syndrome
- With patients with G6PD, what reaction may be caused by certain drugs?
Hemolysis
- What drug can cause patients with seizure disorder problems?
Penicillin G
- Patients with what disorder are more susceptible to neuromuscular blocking effects of certain ABX?
Myaesthenia Gravis
- What must you make sure for Tx of meningitis?
Drug can cross BBB
- Inhibitors of cell wall synthesis, cell membrane disruptors and DNA gyrase inhibitors are what type of ABXóbacteriostatic or bactericidal?
Bactericidal
- Nonaminoglycoside inhibitors of protein synthesis (i.e-macrolides) and antifolates are bactericidal or bacteriostatic?
Bacteriostatic
- True or false: Bacteriostatic ABX slowly degrade the functioning of the cell wall and therefore directly kill the organism
False, bacteriostatic ABX arrest the growth or the replication of bacteria. The host immune system then eliminates the pathogens
- True or False: Resistance means the drug will fail to kill the organism
False, the drug, at high enough doses will kill or inhibit the organism, but that concentration is higher than the safe dose in the human body
- Drug failing to reach target, inactivation of drug, alteration of target (change in binding site) and adaptations that bypass the need for binding site are all causes of what?
ABX resistance
- Transduction, transformation and conjugation(all transferring of plasmids) are what type of resistance?
Acquired
- ABX use resistance is caused by what?
Exerting selective pressure on bacteria to acquire resistance to survive (people not taking the remainder of their ABX, leading to sturdier bacteria)
- What is innate resistance?
A long standing characteristic of a particular species of bacteria
- Conjugation occurs primarily in what type of bacilli?
Gram negative
- What are some of the multiple drug-resistant bacteria?
MRSA, VRE and mycobacteria tubuerculosis.
- Occupy space and compete for essential nutrients, stimulate cross-protective antibodies, suppress growth of potientially pathogenic bacteria and fungi and potiential for pathogenicity are all functions of what?
Host Flora
- What can cause organ damage and inflammation? (slide 4 intro to ID)
Infection and autoimmune disease
- What parameters signify infection?
Fever >37 C (98.6) in adults, erythema of skin, purulence, swelling and leukocytosis
- What cells in immune system recognize self from non self?
Leukocytes
- Average lifespan of leukocytes?
13-20 days
- List components of WBC from largest percentage to lowest. What are the granulocytes?
Neutrophils (50-70%), Lymphocytes (25-35%), Monocytes (2-6%), Eosiniphils (0-6%), Basophils (0-3%)(never let monkeys eat bananas)-basophils, eosinophils and neutrophils are granulocytes (BEN is a bear that says GR)
- What component is drawn to site on infection by chemotactic factors?
Neutrophils
- What are segs?
Multi-lobed nuclei seen in neutrophils
- Production of what is stimulated by interleukins and colony stimulating factors?
Neutrophils
- Increased bands in circulation is referred to what in a CBC with differential?
Left shift
- What does a left shift indicate?
The body is rearing up to fight infectionÖ can also mean leukemia
- What compartment houses the majority of the neutrophils (bone marrow and tissues, circulation or marginated pool)
Bone marrow and tissues
- What would you be sure to monitor in cancer patients in reference to CBC?
Absolute neutrophil count (ANC), the lower it is, the greater chance of infection
- What cells are the effector cells of the immune system, they recognize cells, tag them for removal and kill them. Make antibodies, which have higher percentage?
Lymphocytes, T-cells- 80%, B-cells ñ 20%
- What in WBC components, serves to replenish tissues with macrophages prior to and during immune response?
Monocytes
- What WBC component is responsible for immune processes against helminths (parasitic worms), parasites and are also involved in allergic reactions?
eosinophils
- What WBC components mediate inflammatory response?
Basophils
- Listeria and lactobacillus are what classification of bacteria?
Gram positive bacilli
- What organisms are gram positive cocci?
Streptococcus pyrogens and viridans streptococcus
- What organisms are gram positive pairs?
Streptococcus pneumonia and enterococcus spp
- What organisms are gram positive clusters?
Coagulase positive staphylococcus (S. aureus), coagulase negative staphylococcus (S. epidermis)
- Neisseria meningitidis, Neisseria gonorrhoeae are what type of bacteria?
Gram negative cocci
- E.coli, klebsiella spp., enterobacter spp, proteus spp, serratia marcesens, and pseudomonas spp are all what type of bacteria?
Gram negative bacilli
- What type of bacteria is gram negative coccobacilli?
Haemophilus influenza
- What type of bacteria wall is made up mostly peptidoglycan?
Gram positive
- What is peptidoglycan?
A series of cross-linking (transpeptidases) that help to create the building blocks of the cell wall.
- True or False: Gram negative cell wall is a muli-layered structure
TRUE
- What in gram negative bacteria is one to two glycan chains?
Cell wall
- What in gram negative bacteria protects the cell wall and functions as a penetration barrier? Made of what 3 things?
Lipoprotein outer layer, Made of lipopolysaccharide (LPS), Matrix protein (regulates the influx of molecules), and phospholipids
- What type of bacteria show up on acid-fast staining?
Mycobacterium
- What is the lowest concentration of antibiotic that inhibits visible growth of bacteria?
Minimum inhibitory concentration
- What 2 locations can you have normal colonization of Staphylococci?
Skin and Nose
- Why would you not want to treat staphylococcus species with penicillin?
Large rate of resistance
- What BACTERIA is important to test the vaginal tract in pregnant women and why?
Streptococcus agalactiae- can cause neonatal meningitis.
- What do you use to treat streptococcus?
Penicillin
- What are asplenic patients at risk of developing with infection with S. pneumoniae, H. influenzae, and N. meningitidis
Fulminant sepsis syndrome. Splenic macrophages opsonize and phagocytize encapsulated organisms
- Where are common locations for colonization of pneumococci?
Oropharynx and nasopharnyx
- What should you use to treat pneumococci?
Cephalosporins- may deesculate after getting culture and sensitivities back, switching to penicillin
- Where do you find colonization of enterococci?
GI tract, female genital tract
- After an automobile accident, a 23 year old woman requires an emergency splenectomy. 4 weeks after the surgery, she is brought to the ED unconscious and nonresponsive. The ED physicians are unable to stabilize her and she is brought to the ICU. Blood smear show abundant bacteria. Within 6 hours, the blood culture is reported with gram + cocci. Which organism is the most likely responsible for this overwhelming infection? Coagulase-negative staphylococcus, Methicillin resistant S aureus, Streptococcus pneumonia, Streptococcus pyogenes, Enterococcus faecalis
Streptococcus pneumonia. One of the 3 encapsulated bacteria she gave us. The other two that should be considered is H.influenza, and N. meningitidis
- A 62 year old male is diagnosed with bacterial endocarditis. Blood cultures grow gram + cocci. Which bacterium is most likely? Enterococcus faecalis, Viridans streptococcus, Streptococcus pneumonia, Streptococcus agalactae (2 choices)
Enterococcus faecalis and viridans streptococcus
- What are the most concerning gram negative bacteria she told us to learn?
Enterobacter spp, Escheria coli, Klebsiella pneumonia, Proteus vulgaris, Proteus mirabilis, Serratia marcenera, Pseudomonas aeruginosa
- What species of bacteria is associated with exposure to unclean water (generally in travelers) and found on soil, water and vegetation.
Enterobacteraciae
- Resistance is prevalent and guided by in vitro susceptibility in what species of bacteria due to patterns of resistance?
enterobacteraciae
- Which of the following is NOT found in normal flora? Escheria coli, Staphylcoccus aureus, S. pneumonia, Pseudomonas aeruginosa
Pseudomonas aeruginosa
- What bacteria is seen more often in an immunocompromised patient, after Tx with broad spectrum ABX, and seen with use of ventilation.
Pseudomonas aeruginosa
- What organisms should you double cover on? (Hint SPACE).
Serratia, Pseudomonas, Acinetobacter, Citrobacter, Enterobacter
- True or False: With double coverage, more resistance develops
False, more adverse events occur, but no more resistance has been shown
- True or False: Humans are the only natural host in Haemophilis influenza
False- humans are the only natural host in Neisseria meningitides
- Which strain of Haemophilis influenza is more virulentóencapsulated or no capsule?
Encapsulated
- True or false: Neisseria meningtidis causes pneumonia
True- less common than meningitis, but can still cause pneumonia
- What does the vaccine for H. influenza b and meningococcal vaccine
The polysaccharide in the capsule
- What anaerobes are found above the diaphragm?
Peptostreptococcus spp. (gram+ cocci), Actinomyces spp (gram + rod), Fusobacterium (gram ñ rod)
- What anaerobes are found below the diaphragm?
Bacteriodes fragilis (gram ñ rod), Lactobacillus ( gram + rod), Clostridium spp (gram +rod)
- What type of bacteria usually are penicillinase producers?
Gram negative anaerobes
- Where are anaerobes likely to colonize?
Upper and lower GI tract and vaginal tract
- What characteristics do atypical bacteria have? (3)
Not normal colonizers, not able to gram stain and multiply intracellularly
- What are the atypical bacteria?
Mycoplasma pneumonia, legionella pneumophilia and chlamydophilia pneumonia
- What do atypical bacteria usually result in?
Community acquired pneumonia
- Common etiologies of community acquired pneumonia DO NOT include which of the following? Viridans streptococcus, S. Pneumoniae, Atypicals, H. influenza, All of the above
Viridans streptococcusóthese can cause PNA, but not community acquired. Viridans streptococcus is generally a nosocomial infection
- Which of the following does NOT possess a polysaccharide capsule? Streptococcus pneumonia, H. influenza, Staphylococcus aureus Klebsiella pneumonia, Nieserria meningitis
Staphylococcus aureus
- What bacteria have capsules?
Escheria coli, Streptococcus pneumonia, Salmonella, Klebsiella pneumonia, Haemophilis influenza, Pseudomonas aeruginosa, Neisseria meningitides, Cryptococcus neoformans (yeast)
- Which of the following bacteria produces the enzyme coagulase? Streptococcus pneumonia, Staphylococcus epidermis, Staphylococcus aureus, Klebsiella pneumonia, Neisseria meningitides
Staphylococcus aureus
- What are the nine classes of bacterial pathogens that she told us we should know?
Streptococci, Streptococcus pneumonia, Enterococcus, Staphylococcus, Atypical bacteria, Haemophilis influenza, Gram negative rods, Pseudomonas aeruginosa, anaerobes
- Why are ABX that target cell walls effective at being selective?
Mammalian cells do not have a cell wall
- What are 3 consequences of cell wall inhibition?
Lytic death-cell wall breaks down cell, cell is destroyed, Non-lytic death- dissolves the cell wall inside out, Tolerance- inhibition of growth becoming bacteriostatic (cell shuts down to survive) instead of ñcidal
100.†††††††††††††† What do cell wall inhibitors require for maximal effect?
Actively proliferating microorganisms
101.†††††††††††††† Beta-lactam abx, vancomyocin, daptomyocin and bacitracin are major members of what?
Inhibitors of cell wall synthesis
102.†††††††††††††† Beta lactam drugs are inherently unstable to what?
pH and beta lactamases
103.†††††††††††††† What type of drugs undergo acylation (form covalent bond with a trans-peptidase)
Beta-lactams
104.†††††††††††††† Beta lactam drugs are generally _______ and most active __________
Bactericidal;against growing organisms
105.†††††††††††††† By substituting side chains, antimicrobial spectrum, absorption, characteristics, resistance to what occurs with penicillin?
Resistance to lactamase deactivation can be altered
106.†††††††††††††† What step does penicillin interfere with?
Last step
107.†††††††††††††† What are penicillin-binding proteins? What do they do?
The place where penicillins bind to and inhibit transpeptidases. These enzymes are responsible for catalyzing the cross linking of peptidoglycans, creating an osmotically unstable membrane, which ruptures the bacterial cell
108.†††††††††††††† As a bacteriocidal agent, penicillins require what to work the best?
Rapidly proliferating organisms
109.†††††††††††††† True or false: Penicillins will be effective against protozoa, mycoplasma, mycobacteria, fungi and viruses
False. Penicillin will be ineffective d/t lack of cell wall in this organisms
110.†††††††††††††† What 3 methods of resistance are there to penicillins?
inactivation by beta lactamase (most common), modification of PBP target (mechanism of MRSA), impaired penetration of drug to target PBP
111.†††††††††††††† Penicillin G is wide or broad spectrum?
Narrow
112.†††††††††††††† Which version of penicillin is acid labile? (and therefore not available in a tablet)
Penicillin Góavailable only in an injection
113.†††††††††††††† True or false: Penicillin is highly active against staphylococcus
False, it is highly active against gram positive cocci EXCLUDING staphylococcus
114.†††††††††††††† What ABx is commonly used for Tx of infections of upper/lower respiratory tract, throat, skin, GU tract and prophylaxis for rheumatic fever, dental proceedures for those at risk of endocarditis, gonorrhea or syphilis exposure?
Penicillin G or V
115.†††††††††††††† What is Clavulanic acid and sublactam? What do they do?
Beta-lactamase inhibitors, extend the spectrum of abx its paired with, increases coverage of H. flu, some staph and Moraxella catarrhalis
116.†††††††††††††† What are the penicillinase resistant penicillins? (still available in US)
Nafcillin, oxacillin and dicloxacillin
117.†††††††††††††† True or False: Penicillinase-resistant drugs are broad spectrum
False, they target specifically the penicillinase resistant drugs, so they are narrow spectrum.
118.†††††††††††††† True or False: MRSA can be treated with Oxacillin
False- MRSA is resistant to even the penicillinase-resistance penicillins
119.†††††††††††††† What is a suicide inhibitor?
Beta-lactamase inhibitor, which is a potent irreversible inhibitor ofmany (but not all) lactamases
120.†††††††††††††† Should you take food with penicillins?
No, it may decrease the absorption of available oral penicillins
121.†††††††††††††† Do penicillins cross the BBB?
Only when the meninges are inflamed
122.†††††††††††††† Would you use penicillins to treat prostate infections?
No, they have a problem penetrating the prostate, eye and CNS
123.†††††††††††††† True or False: penicillins do not require p450 metabolism
True, they are not metabolized but are dependent on the kidney for elimination
124.†††††††††††††† What things might you want to monitor with penicillins?
LFTs (for hepatitis with oxacillin), CBC (for neutropenia with nafcillin) and CBC with platelet count (for abnormal platelet aggregation with ticarcillin and carbenicillin)
125.†††††††††††††† What drug can anti-pseudomonal PCN affect the metabolism of?
Warfarin, donít need to avoid giving with this, but you should adjust the dose of your warfarin
126.†††††††††††††† What drug or drugs with which MOA should you not give with PCN and why?
Tetracycline or other bacteriostatic agents, bacteriostatic agents shouldnít be given with bactericidal agents because they make PCN less effective.
127.†††††††††††††† Are cephalosporins safe in pregnancy?
Yes they are category B
128.†††††††††††††† What do you give for patients for a gram positive infection that is allergic to penicillins?
1st generation cephalosporinÖ but there is still a 10% chance of cross reactivity reaction
129.†††††††††††††† Do 1st or 2nd generation cephalosporins have greater gram negative coverage?
2nd generation
130.†††††††††††††† What 3rd generation cephalosporin has anti-pseudomonal coverage?
Ceftazidime
131.†††††††††††††† What ABX is used for penicillin resistant pneumococcus?
3rd generation cephalosporin
132.†††††††††††††† What generation cephalosporin has the greatest gram positive coverage?
1st generation>4th generation>2nd generation or 3rd generation
133.†††††††††††††† What generation cephalosporin generations have the best gram negative coverage?
2nd and 3rd generation (equally)>1st generation
134.†††††††††††††† What cephalosporins can cross into BBB?
Cefuroxime, cefotaxime, ceftriaxone, cefepime
135.†††††††††††††† What side effect is specific to ceftriaxone?
Cholelithiasis due to precipitant in bile
136.†††††††††††††† What side is found throughout the cephalosporin class?
Blood dyscrasiasóthey resolve with the DC of the drug
137.†††††††††††††† What should you warn your patients about when taking cefoperazone and cefotetan? (with methylthiotetrazole side chains)
With ingestion of alcohol, even a tiny bit, makes the person violently ill
138.†††††††††††††† What is the most broad spectrum abx of beta-lactam class of antibiotics? These are resistant to many beta-lactamases
carbapenems
139.†††††††††††††† What does cilastin do when in combination with imipenem?
Inhibits dehydropeptidase I. This enzyme (dehydropeptidase) inactivates imipenem by breaking the beta-lactam ring. Other carbapenems are not sensitive to dehydropeptidase
140.†††††††††††††† What side effect can be expected with carbapenems when not adjusted for patients with renal failure?
Seizures
141.†††††††††††††† Can you give carbapenems to someone with penicillin?
No, there is a high degree of cross sensitivity between these two classes
142.†††††††††††††† You should be cautious about when Rxing meropenem for epileptic patients?
Meropenem reduces valproic acid levels. Need to Adjust for this
143.†††††††††††††† What in the carpapenems would you not give to a pregnant lady?
The imipenem/cilastin combo
144.†††††††††††††† What would you give for a patient who was allergic to penicillin and cephalosporin for a gram negative infection?
Monobactams (Aztreonam)óthere is no cross reactivity with PCN or cephalosporin, and they are resistant to most beta-lactamases (which is important because most gram negatives produce the beta lactamase)
145.†††††††††††††† What drugs interact with aztreonam? What toxicities are associated?
None- there are no reported drug interactions, no major toxicity.
146.†††††††††††††† What ADRs are associated with cycloserine?
CNS toxicity (reversible with pyridoxineóB6), Renal impairment will accelerate toxicity
147.†††††††††††††† What two types of resistance is seen with vancomyosin?
Acquired (plasmid born), Innate- outer membrane in gram negatives resist penetration
148.†††††††††††††† What types of bacteria is vancomysin effective against? (what does it cover)
Gram positive only- including beta-lactamase producing varieties (this has no beta-lactam ring)
149.†††††††††††††† What ABX is reserved for patients with allergic reactions to beta lactams suffering from serious gram positive infections
for infections resulting from methicillin resistant S. aureus.
Used in abx associated enterocolitis
Vancomycin
150.†††††††††††††† What organism is responsible for antibiotic associated enterocolitis?
C. diff
151.†††††††††††††† Why is vancomycin the drug of choice for superinfection (abx associated enterocollitis)?
It is a gram positive abx (vancomycin is effective towards gram positive only), most of the normal flora is gram negative, and it is not absorbed when given orally
152.†††††††††††††† What should you be treating when giving vancomycin orally?
Treatment of C. difficile induced colitis
153.†††††††††††††† How should vancomycin be administered when treating a patient who is allergic to penicillin and is having a serious gram positive infection?
IV
154.†††††††††††††† What is half life of vancomycin directly dependent on?
Creatinine clearance- can be markedly prolonged depending on the degree of renal insufficiencyóyou wouldnít avoid giving this in renal insufficiency, just adjust the dosage to account for the change
155.†††††††††††††† What is the main indication for parenteral (IV) vancomycin?
MRSA or methicillin resistant staph epi (which includes endocarditis, sepsis, osteomyelitis and wound infections)
156.†††††††††††††† What would you give for penicillin reistant pneumococcus?
Vancomycin
157.†††††††††††††† What abx has adverse effects including red man syndrome, local and infusion reactions, phlebitis, ototoxicity and nephrotoxiticity?
Vancomycin
158.†††††††††††††† Is ototoxicity associated with vancomycin reversible?
No, once the damage occurs, it is there for life.
159.†††††††††††††† What levels do you want to get with vancomycin?
Trough levels- to monitor efficacy. Renal function tests
160.†††††††††††††† What is oritavancin approved for?
Gram + organisms (including MRSA), approved for skin infections
161.†††††††††††††† What is the half life elimination of oritavancin?
245 hours
162.†††††††††††††† How is bacitracin administered? Why?
Topical, very nephrotoxic
163.†††††††††††††† What is bacitracin often combined with to wash out surgical wounds?
Neomycin or polymixin
164.†††††††††††††† Linezolid is static for what bacteria, and cidal for what bacteria?
Static for enterococci, Cidal for streptococci
165.†††††††††††††† Aminoglycosides have little activity in abscesses, why is this?
Aminoglycosides gain access to cell membranes via porin channels which are inhibited by acidic pH and aerobic conditions
166.†††††††††††††† Aminoglycosides have a synergistic reaction with what 2 classes of abx?
Peniciilins and cephalosporins- which are cell wall active abx
167.†††††††††††††† What are the 3 known mechanisms of resistance in aminoglycosides?
Modification of aminoglycoside molecule by enzymes (canít bind the ribosome), Binding of aminoglycosides on rRNAaltered
Reduced uptake of aminoglycosides
168.†††††††††††††† What do we use to combat resistance with aminoglycosides?
Agents that target cell wall in conjunction with aminoglycosides
169.†††††††††††††† What type of bacteria do aminoglycosides target?
Aerobic gram negative (Klebsiella spp, enterobacter, and pseudomonas aeruginosa). little acitivity against anaerobes and gram + organisms
170.†††††††††††††† When do we use aminoglycosides in combination with other agents?
To broaden coverage in serious illness (bacteremia or sepsis or pseudomonal infections), and in synergism with vancomycin or penicillins in the treatment of endocarditis
171.†††††††††††††† What class of abx exhibit concentration dependent killing and have a pronounced post-antibiotic effect?
Aminoglycosides
172.†††††††††††††† What is post antibiotic effect?
Microbial growth suppression after course of abx has finished
173.†††††††††††††† What are the most widely used aminoglycosides?
Gentamycin, tobramycin and amikacin. There is cross resistance between these drugs
174.†††††††††††††† What aminoglycosides are limited to oral or topical? Why?
Neomycin or kanamycin d/t toxicity
175.†††††††††††††† What is used for Tx of gonorrhea in PCN allergic patients?
spectinomycin
176.†††††††††††††† What class of ABX have adverse effects including ototoxicity, nephrotoxicity (both of those are increased with increased duration of therapy), and neuromuscular blockade? With rare reactions including optic nerve dysfunction, peripheral neuritis, encephalopathy, pancytopenia, exfoliative dermatitis and amblyopia
Aminoglycosides
177.†††††††††††††† What are symptoms of cochlear toxicity?
High pitched tinnitus, progressing to high pitch deafness
178.†††††††††††††† Sx of vestibular toxicity?
HA, N,V and vertigo
179.†††††††††††††† What adverse effect is generally not an issue in healthy people?
Neuromuscular blockade. This aggravated muscle weakness, leading to respiratory paralysis in myasthenia gravis or parkinsonís disease due to curare like effect
180.†††††††††††††† What allergy should you be cautious of when Rxing streptomycin?
SulfITE allergies- streptomycin contains metabisulfite
181.†††††††††††††† What aminoglycoside is used for decontamination of bowel?
Neomycin orally. No oral absorption. Too toxic for IV.
182.†††††††††††††† Is volume of distribution higher or lower in obese people taking aminoglycosides?
Lower- it is insoluble in lipids
183.†††††††††††††† For what class of abx is clearance proportional to creatinine clearance?
Aminoglycosides- adjustments must be made to avoid accumulation. Usually you adjust dose or interval to maintain peak and trough levels within a desired range in renal insufficiency
184.†††††††††††††† What type of diuretic is going to cause increased nephrotoxicity when given with aminoglycosides?
Loop diuretics
185.†††††††††††††† What aminoglycosides can cause 8th cranial nerve toxicities in fetus, and is therefore categorized as class D drugs?
Amikacin, streptomycin, tobramycin and kanamycin
186.†††††††††††††† What class of abx covers gram positive, gram negative, aerobic, anaerobic,mycoplasma pneumonia, chlamydia (pneumonia and trachomatis), rickettsia(RMSF), borrelia burgdorferi (lyme disease), inflammatory acne, sinusitis and malasoption due to bacterial overgrowth?
Tetracyclines
187.†††††††††††††† What are the 3 groups based on pharmacokinetics in tetracyclines?
Short-acting, Intermediate-acting, Long-acting
188.†††††††††††††† What tetracycline is no longer used as an antibiotic? What is it used for?
Demeclocycline, Tx of SIADH
189.†††††††††††††† What is the most important mechanism of resistance in tetracyclines?
Bacterial efflux pump- resistance is encoded on a multi-drug resistance gene that is carried and shared via plasmids
190.†††††††††††††† What is one of the biggest offenders of causing C.diff?
Tetracyclines
191.†††††††††††††† What class of drug includes ADRs of N,V,D (most common), modified GI flora, binding to bony structures, photosensitization, dizziness, vertigo, pseudotumor cerebri and lupus like reaction?
Tetracycline
192.†††††††††††††† What would you expect with a patient taking tetracyclines and drinking dairy, aluminum hydroxide, Ca, Mg, iron or zinc and bismuth sulfate.
These all bind to tetracycline, meaning tetracycline will never be absorbed- no reaction
193.†††††††††††††† What was third generation tetracycline (TCN) developed for?
To overcome bacterial resistance mechanisms to TCNs (efflux and ribosomal mutations)
194.†††††††††††††† What medication, because of its blood dyscrasias, is reserved for life-threatening infections such as typhoid fever, RMSF and meningitis in patients allergic to penicillin
Chloramphenicol
195.†††††††††††††† What causes the blood dyscrasias associated with chloramphenicol?
One of its MOA is to inhibit mitochondrial protein synthesis in mammalian cells
196.†††††††††††††† What contraindications are associated with chloramphenicol? What ADRs?
Never used in pregnant women or neonates. The ADRs are myelosuppression, reversible anemia, neutropenia and thrombocytopenia, and in neonates, gray baby syndrome (pallor, abdominal distention, vomitin and collapse)
197.†††††††††††††† Which of the following are not semisynthetic derivatives: azithromycin, erythromycin and azithromycin? What is the benefit of being a semisyntheic macrolide?
Erythromycin. Semisynthetics are derived from erythromycin, are more acid stable, have better tissue penetration and are broader spectrum.
198.†††††††††††††† Are macrolides bacteriostatic or bactericidal?
Bacteriostatic, but at high concentrations or with rapid bacterial growth, they can be bactericidal.
199.†††††††††††††† Which of the following would you not Rx for anaerobic coverage? Azithromycin, erythromycin or clarithromycin?
Erythromycin, no anaerobic coverage
200.†††††††††††††† H. influenza is resistant to what macrolide? If you still want to treat H. influenze with this one, what combo could you use?
Resistant to erythromycin, but you can combo with a sulfonamide. Pediozole= erythromycin+athylsuccinate+sulfosoxisole
201.†††††††††††††† What must be done with an oral tablet of erythromycin?
Must be coated with enteric coating because the base in erythromycin is destroyed by acid
202.†††††††††††††† If someone is on IV erythromycin, what would you need to monitor for?
IV erythromycin can cause QT prolongation, need to be placed on heart monitor to watch for this.
203.†††††††††††††† What are 2 advantages of clarithromycin over erythromycin?
It includes enhanced coverage of atypical mycobacteria AND there is less GI upset and BID dosing (where as erythromycin is TID)
204.†††††††††††††† What is the coverage of azithromycin more targeted to?
Increased staph and strep coverage, decreased stypical mycobacteria and H. influenza coverage
205.†††††††††††††† What macrolide has great tissue penetration and prolonged intracellular half-life
Azithromycin
206.†††††††††††††† If someone is taking a lot of medications metabolized trhough the p450, what macrolide would you Rx and why?
Azithromycin, this is the only macrolide not metabolized by CYP3A4. Erythromycin and clarithromycin are substrated and inhibitors of CYP3A4. These two have LOTS of drug interactions, the ones she mentioned were statins, ergots, digoxin, carbamazepine and warfarin
207.†††††††††††††† Taking cisapride is contraindicated with what 2 macrolides?
Erythromycin and clarithromycin
208.†††††††††††††† What class of drugs are a semisynthetic derivative of erythromycin, displays greater potency against gram positive organisms and displays activity against macrolide resistant strains?
Ketolides. These do not induce bacterial methylase (mechanism of resistance), and the drug is able to bind to 50S subunit when site is methylated (mechanism of resistance)
209.†††††††††††††† What black box warning is associated with telithromycin?
Linked to liver failure and deaths; increased risk of ventricular arrhythmias; and a contraindication of people with myasthenia gravis never taking this medication.
210.†††††††††††††† What is the most important indication associated with clindamycin (which is a lincosamide)
Tx of anaerobic or mixed (polymicrobial) infections. Used to Tx infections of female genital tract (inpatient PID, septic abortion or amnionitis), decubitus venous stasis or arterial insufficiency ulcers and aspiration pneumonia. Also seen as topical Tx of mild inflammatory acne
211.†††††††††††††† What is the MOST COMMON abx to cause C. diff toxin mediated diarrhea?
Clindamycin
212.†††††††††††††† What medications (there are 2 of them) that are indicated for life-threatening infections associated with VRE bacteremia and Tx of complicated skin/structureinfections by methicillin susceptible S. aureus or S. pyrogenes?
Quinupristin and dalfopristin (streptogramins), these are the only indications for this!
213.†††††††††††††† What are the two oxazalidinones, and what are their indications?
Linezolid and tedizolid, indicated in vanco-resistant enterococcus faecium (VRE), nosocomial pneumonia d/y S. aureusóincluding MRSA or S. pneumonia; un/complicated skin/skin structure infections and gram positive CAP
214.†††††††††††††† Is linezolid bacteriostatic/cidal against enterococci and staph and strep?
Static against enterococci and staph; bactericidal against strep.
215.†††††††††††††† What should be concerned of developing when Rxing linezolid in combination with andernergic and serotonergic drugs?
hypertension
216.†††††††††††††† what does highly protein bound mean? What does this effect?
The drug is bound to a number of plasma proteins, primarily albumin. This has a great effect on half-life and tissue penetration. Minimally protein bound = better tissue penetration
217.†††††††††††††† Adverse drug reactions for tidizolid?
Nausea, headache and concern for C. diff
218.†††††††††††††† What is the indication for mupirocin?
Active against gram positive cocci, used for Tx of skin- ie. impetigo
219.†††††††††††††† What are the 2 enzyme target for bacterial folate antagonists?
Dihydropteroate synthetase and dihydrofolate reductase
220.†††††††††††††† Are sulfonamides bacteriostatic or bactericidal?
Bacteriostatic against gram positive and gram negative
221.†††††††††††††† What are the 3 major groups of sulfonamides?
Oral absorbable, oral nonabsorbable and topical agents
222.†††††††††††††† Most commonly used oral absorbable sulfa?
sulfamethoxazole
223.†††††††††††††† What are the adverse effects of sulfonamides?
N/V/D, HA and photosensitivity
224.†††††††††††††† What can happen as a result of taking sulfonamides during pregnancy near term?
Neonatal kernicterus
225.†††††††††††††† If you give someone trimethoprim, and they develop megaloblastic anemia, leukopenia or granulocytopenia, what do you do to reverse this?
Folinic acid
226.†††††††††††††† True or false: trimethoprim has similar spectrum to sulfonamides, but it is less potent
False, it is more potent
227.†††††††††††††† What is the only available IV sulfonamide antibiotic?
Sulfamethoxazole/trimethoprim (Bactrim or septra)
228.†††††††††††††† True or False: sulfamethoxazole is used to treat C. diff.
False, it is used to treat bacterial diarrhea, but a travelerís diarrhea.
229.†††††††††††††† What class of drugs works by blocking bacterial DNA synthesis by inhibiting DNA topoisomerase IV and topoisomerase II (DNA gyrase)
Quinolones
230.†††††††††††††† Activity against what accounts for gram positive spectrum?
Topoisomerase IV
231.†††††††††††††† What are the quinolone ìclassesî?
Excellent gram negative coverage with only moderate gram positive activity(cipro). Excellent gram negative coverage with improved gram positive coverage (levofloxacin and moxifloxacin). Continued gram negative and gram positive coverage with enhanced anaerobic coverage (trovafloxacin)
232.†††††††††††††† What atypical pneumonia do quinolones cover?
Chlamydia pneumonia and mycoplasma penumoniae.
233.†††††††††††††† What intracellular pathogens are covered by quinolones?
Legionella, mycobacteria tuberculosis and mycobacteria avium complex
234.†††††††††††††† What fluroquinilone is restricted by FDA for life or limb threatening infections due to severe hepatic toxicity?
Trovafloxacin
235.†††††††††††††† What is resistance in fluroquinilones due to?
One or more point mutations on bacterial chromosomes (change in binding site and decreased permability)
236.†††††††††††††† In elderly patients taking glucocorticoids and quinolones, what is a ADR that might occur?
Tendinitis and tendon rupture
237.†††††††††††††† What quinolone is more likely to have interactions with CYP system?
Ciprofloxacin- methadone and theophylline levels increase and severe fatal hypoglycemia with concurrent use of glyburide
238.†††††††††††††† What coverage does metronidazole have?
Anaerobic and protozoan infections
239.†††††††††††††† Metronidazole is contraindicated in pregnant in what trimester?
1st, class B in 2nd and 3rd
240.†††††††††††††† What drug interaction should you warn your patient about with metronidazole?
Disulfiram like reaction with alcoholóviolently ill with the smallest exposure to alcohol
241.†††††††††††††† Why is nitrofurantoin biggest indication in UTIs?
It reaches high concentrations in the urine, making it ideal for treating UTIs
242.†††††††††††††† True or False: resistance to polymixin B is high.
False, resistance is low
243.†††††††††††††† What is the spectrum for polymixin B?
Gram negative bacteria, including pseudomonas aeruginosa
244.†††††††††††††† What route is preferred in polymixin B administered and why?
Topical due to high nephron and neuro toxicity. Topical solutions used in gut sterilization, bladder irrigation and ophthalmic. Used in combination for topical applications. IV, IM, and intrathecal are available, but reserved for hospitalized patients with serious infections.
