Antibacterials Flashcards
False about Natural penicillin:
A. Good against Streptococci and Meningococci
B. Good against Staphylococci
C. Repository formula= Penicillin G Benzathine
D. Oral preparation= Phenoxymethy penicillin
B
In addition to Penicillin G, aminopenicillin has added activity to:
A. Corynebacterium diphtheriae
B. Staphylococcus
C. Listeria monocytogenes
D. Streptococcus
C
True for Piperacillin-Tozabactam except:
A. Most broad spectrum available in the Philippines
B. With anaerobic activity
C. For MRSA
D. For P. aeruginosa
C
Compared to a 1st gen cephalosporin, a 3rd gen cephalosporin would be expected to exhibit?
A. improved activity against certain gram negative bacteria
B. lower levels of activity in the CSF
C. improved inhibition of folate synthesis by sensitive bacteria
D. AOTA
A
Which among the ff statements about cefazolin is FALSE:
A. It is effective against Staphylococcus aureus and Streptococcus
B. It has good oral bioavailability.
C. It may used for skin infections and cellulitis.
D. It has no activity against enterococcus.
B
What is the advantage of using Cefepime over Ceftazidime?
a. lesser activity against gram positive bacteria
b. higher activity against Chlamydia
c. better activity against gram negative bacteria
d. should be used in all cases in the ER
C
For an antibacterial antibiotic to be effective, it must first gain access to the target sites of action, that is or in the human host cell. T/F
T
The basic mechanism of action of beta-lactam antibiotics is inhibition of nucleic acid synthesis or function. T/F
FALSE; Beta-lactams inhibit cell wall synthesis
Compared with other pharmacological agents, antibacterial chemotherapeutic agents are reasonably safe. T/F
FALSE; Vague question, safety is relative and some antibacterials are more toxic than the others.
The word antibiotic is now often used to include antimicrobial agents, produced by microorganisms and those that are totally synthetic. T/F
T
Amoxicillin
A. Aminopenicillin B. Carboxy Penicillin C. Natural Penicillin D. Penicillinase-resistant penicillin E. Ureide Penicillin
A
Benzyl Penicillin
A. Aminopenicillin B. Carboxy Penicillin C. Natural Penicillin D. Penicillinase-resistant penicillin E. Ureide Penicillin
C
Carbenicillin
A. Aminopenicillin B. Carboxy Penicillin C. Natural Penicillin D. Penicillinase-resistant penicillin E. Ureide Penicillin
B
Cloxacillin
A. Aminopenicillin B. Carboxy Penicillin C. Natural Penicillin D. Penicillinase-resistant penicillin E. Ureide Penicillin
D
Piperacillin
A. Aminopenicillin B. Carboxy Penicillin C. Natural Penicillin D. Penicillinase-resistant penicillin E. Ureide Penicillin
E
The beta-lactam antibacterial antibiotics include the following EXCEPT:
A. Penicillin V
B. Cefuroxime
C. Meropenem
D. Cilastatin
D
This third generation cephalosporin is relatively resistant to hydrolysis by beta-lactamases and has the broadest gram-negative spectrum
A. Cefepime
B. Ceftriaxone
C. Cefuroxime
D. Cephalexin
B
Penicillin of choice for Streptococcus pyogenes is
A. Penicillin G
B. Penicillin V
C. Cloxacillin
D. Amoxicillin
A
Depot formulations of Penicillin G i.e., Benzathine Penicillin G and Procaine Penicillin G are inappropriate for meningitis
A. True
B. False
A
The activity of extended spectrum penicillins goes beyond that of the aminopenicillins as it is active against
A. Staphylococci
B. Streptococci
C. Enterococci
D. Pseudomonas
D
Appropriate specimen collection from the infected organ system should be done day after starting antibiotic therapy-
F
in treating bacterial infection in immunocompromised patient, such as those with leukemia a bacteriostactic agent is sufficient. T/F
F
The Beta-Lactam Antibacterial antibiotics are selectively toxic. Selective toxicity is
a. What the drug does to the patient
b. What the patient does to the drug
c. What the pathogen does to the patient
d. What the drug does to the pathogen
e. What the pathogen does to the drug
D
All of these drugs are beta-lactam antibiotics EXCEPT
a. Ampicillin
b. Aztreonam
c. Cephalexin
d. Gentamycin
e. Imipenem
D
The basic mechanism of action of beta-lactam antibiotics is
a. Inhibition of bacterial protein synthesis
b. Inhibition of mycolic acid synthesis
c. Inhibition of cell wall synthesis
d. Inhibition of cell membrane function
e. Interference of microbial folic acid synthesis
C
In order to use Beta-Lactam antibiotics effectively and safely the following principles may be followed
a. Determine the pathogen causing the infection
b. Choose the right drug
c. Administer the drug properly
d. Prevent/minimize adverse drug reaction
e. All of the above
E
Having a previous hypersensitivity reaction to penicillin G would also predispose the patient to having a hypersensitivity reaction to another penicillin like piperacillin. T/F
TRUE. Penicillins exhibit cross-allergenicity, meaning their structures are sufficiently similar to elicit similar hypersensitivity reactions. From Katzung: “All penicillins are cross-sensitizing and cross-reacting.” (12th edition, p.796).
In treating bacterial infections in immunocompromised patients, such as those with leukemia, a bacteriostatic agent is insufficient. T/F
TRUE. Bacteriostatic agents do not completely eliminate bacteria, they simply prevent bacteria from reproducing. These bacteria may then continue to grow in more favorable conditions, such as when host defenses go down or when the bacteriostat is removed. Thus, bacteriostatic agents work best in conjuction with intact host defenses. In immunocompromised patients, this would be detrimental as they are not able to mount a strong enough immune response.
Physicians may follow the typhoid treatment guidelines for India for treatment of patients with typhoid in the Philippines. T/F
FALSE. Statistics where these guidelines are based will not be the same across countries. Parameters such as prevalence or antibiotic resistance, for example, will differ.
Updating treatment guidelines for infectious diseases is not necessary. T/F
FALSE. It is necessary because bacteria continuously evolve, drug research is a very active field, resistance patterns often change, etc.
Resistance patterns for Streptococcus pneumonia are similar all over the world. T/F
FALSE. Resistance patterns depend on a variety of factors such as government control programs, sanitation, and health practices. These would differ across countries.
Physicians must have current knowledge on the epidemiology of infectious disease in their locality. T/F
TRUE. Some infectious diseases are endemic to particular regions, prevalence rates may be higher for a certain region compared to another, and physicians must be aware of these in order to properly manage their patients.
In which class does the following belong: Erythromycin
Macrolides
In which class does the following belong: Cotrimoxazole
Sulfonamide-trimethoprim
In which class does the following belong: Ciprofloxacin
Quinolones
In which class does the following belong: Tetracyclines
Tetracyclines
In which class does the following belong: Cefepime
Cephalosporins (4th gen)
In which class does the following belong: Ampicilin
Aminopenicillins
In which class does the following belong: Vancomycin
Glycopeptides
Penicillins
A. Inhibitor of protein synthesis
B. Inhibitor of folate metabolism
C. Inhibitor of DNA gyrase
D. Inhibitor of cell wall synthesis
D
Macrolides A. Inhibitor of protein synthesis B. Inhibitor of folate metabolism C. Inhibitor of DNA gyrase D. Inhibitor of cell wall synthesis
A
Tetracyclines A. Inhibitor of protein synthesis B. Inhibitor of folate metabolism C. Inhibitor of DNA gyrase D. Inhibitor of cell wall synthesis
A
Quinolones A. Inhibitor of protein synthesis B. Inhibitor of folate metabolism C. Inhibitor of DNA gyrase D. Inhibitor of cell wall synthesis
C
Sulfonamide-trimethoprim A. Inhibitor of protein synthesis B. Inhibitor of folate metabolism C. Inhibitor of DNA gyrase D. Inhibitor of cell wall synthesis
B
\_\_\_\_\_\_\_\_\_ is a semi-quantitative antibiotic susceptibility test using paper discs impregnated with an antibiotic and after incubation with the bacteria to be test, the zone of inhibition is measured. A. Kirby-Bauer method B. Broth dilution test C. Minimum inhibitory concentration D. Hudgen’s test
A
A. Intro to Antipathogens and Antimicrobials trans. Also known as the disc diffusion assay. A lawn of bacteria is cultured with antiobiotic-impregnated discs and zones of clearing around the discs are measured. If the diameter of the zone is greater than a certain size, the bacteria is susceptible to the antibiotic in the disc, but if the diameter is below the defined size, the antibiotic will most likely not inhibit the bacteria
The following data is given for a disk diffusion test using N. gonorrhea and ceftriaxone:
Zone diameter breakpoint with Ceftriaxone
Sensitive: 35
Resistant: 34
The zone diameter seen for the isolate of N. gonorrhea from the penile discharge was 30 mm.
Which of the following is a correct statement.
A. The patient will most likely have poor response to ceftriaxone
B. The patient most likely will be cured with ceftriaxone
C. It is safe to give the patient 10x the dose of ceftriaxone to ensure cure
A. The smaller the zone of clearing around the disc, the more the bacteria is resistant to the drug in the disc.
In comparison to the natural penicillins, the aminopenicillins have added activity against A. Pseudomonas aeruginosa B. Listeria monocytogenes C. Staphylococcus aureus D. Bacteroides fragilis
D.
Listeria monocytogenes and Staphylococcus aureus are gram positive. Pseudomonas aeruginosa and Bacteroides fragilis are gram negative, but ampicillin is not active against P aeruginosa (Katzung, 12 ed, p. 796)
True of oxacillin EXCEPT
A. Has good activity against staphylococcus
B. May be given for Klebsiella pneumoniae
C. Has a short half-life
D. Has good activity against streptococcus
B.
Oxacillin CLASS: Penicillins, anti-staphylococcal. Resistant to staphylococcal B-lactamases, but can also be used against streptococci. This cannot be used against gram-negative bacteria as well as enterococci and anaerobic bacteria. K. pneumoniae is gram-negative.
The following statement is true of piperacillin EXCEPT
A. It is an extended spectrum penicillin
B. Has activity against anaerobes
C. May be used for methicillin-resistant S. aureus infections
D. Is effective against P. aeruginosa sepsis
C
Expected adverse effects of penicillins EXCEPT
A. Ototoxicity
B. Allergic reactions
C. Diarrhea
D. Interstitial nephritis
A
From Katzung: “The penicillins are generally well tolerated…Most of the serious adverse effects are due to hypersensitivity…Oral lesions, fever, interstitial nephritis (an autoimmune reaction to a penicillin-protein complex)…may also occur…Large doses of penicillins give orally may lead to gastrointestinal upset, particularly nausea, vomiting and diarrhea. (12th edition, p. 796.)
Rina is a 2 day old neonate born to a mother diagnosed with untreated syphilis. The penicillin of choice is: A. Amoxicillin-clavulanic acid B. Piperacillin-tazobactam C. Oxacillin D. Pen G
D
Cefuroxime is useful for treatment of infections caused by the following pathogens EXCEPT A. Hemophilus influenza B. E. coli C. S. pneumonia D. Legionella
D.
Cefuroxime is a second-generation cephalosporin. From Katzung: “In general, they [second-gen cephalosporins] are active against organisms inhibited by first-generation drugs (in pertaining to first generation drugs: these drugs are very active against gram-positive cocci, such as pneumococci, streptococci and staphylococci)…E. coli, K. pneumonia and P. mirabilis are often sensitive…Cefamandole, cefuroxime, cefmetazole, ceforanide, and cefaclor are active against H. influenzae.” Legionella is a gram-negative microorganism, which second-gen cephalosporins have poor activity against.
True of tetracycline EXCEPT
A. Has good activity against intracellular bacteria such as legionella and chlamydia
B. Is safe for long term use in patients less than eight years old and pregnant women
C. Long acting preparations can be given once a day or every 12 hours
D. Side effect include photosensitivity, hepatotoxicity, and SLE
B.
From Katzung: “Tetracyclines are readily bound to calcium deposited in newly formed bone or teeth in young children…during pregnancy, it can be deposited in the fetal teeth…Because of these effects, tetracyclines are generally avoided in pregnancy. If the drug is given for long periods to children younger than 8 years, similar changes can result.” (12th edition, p. 812)
Erythromycin is used as an alternative drug for penicillin for many indications EXCEPT A. S. pneumonia pneumonia B. Mycoplasma pneumonia C. Rheumatic fever prophylaxis D. Syphilis
B
What is a correct indication for the usage of chloramphenicol? A. Malaria B. Typhoid fever C. Staphylococcal impetigo D. Otitis media
B
From Medscape: “For sensitive strains, still most widely used antibiotic to treat typhoid fever.”
True of ciprofloxacin A. It is the drug of choice for MRSA B. It has good activity for S. pneumonia C. It inhibits topoisomerase II and IV D. It is active against plasmodium
C.
From Katzung: “Quinolones block bacterial DNA synthesis by inhibiting bacterial topoisomerase II (DNA gyrase) and topoisomerase IV.” (12th edition, p. 835)
Antimicrobial agents that are avoided during pregnancy are the following EXCEPT A. Ciprofloxacin B. Cotrimoxazole C. Doxycycline D. Cefixime
D.
From Medscape: “Pregnancy category B (may be acceptable. Either animal studies show no risk, but human studies not available or animal studies showed minor risks and human studies done and showed no risk.)”
Adverse effects of chloramphenicol include the following EXCEPT A. Gray baby syndrome B. Red man syndrome C. Idiosyncratic aplastic anemia D. Dose-related bone marrow depression
B.
From Medscape, grey baby syndrome, aplastic anemia and bone marrow depression are all listed under adverse effects. Red man syndrome (so-called because of the erythematous rash that appears in the face and upper body) is more related to IV-infused vancomycin.
The disadvantage of using erythromycin in comparison to newer macrolides for respiratory tract infections is that erythromycin has poor activity for A. S. pneumonia B. Legionella C. H. influenza D. Chlamydia
C
From Katzung: “Erythromycin is active against susceptible strains of gram-positive organisms, especially pneumococci, streptococci, staphylococci, and corynebacteria…Chlamydia trachomatis, Chlamydia pneumonia are susceptible…H. influenzae is somewhat less susceptible.
True about identifying the etiologic agent in the treatment of infectious diseases
A. It is essential in choosing the correct antimicrobial to prescribe
B. Serology is the gold standard for most bacterial infections
C. Gram stain and cultures are usually optional for most bacterial infections
D. Antibiotic susceptibility testing should not be performed on the bacteria cultured.
A
Antibiotic resistant strains have been documented for this/these bacteria in the Philippiines EXCEPT: A. Neisseria gonorrhea B. Staphylococcus aureus C. Haemophilus influenzae D. Neisseria meningitides
D
Which statement is FALSE about natural penicillins?
A. It has good activity against Treponemes
B. The repository formulation is phenoxymethylpenicillin
C. It has good activity against pneumococci
D. The oral formulation is PenVK
B
True of Oxacillin EXCEPT:
A. It has good activity against E. coli
B. It may be given for staphylococcus pneumonia
C. It has a short half-life
D. It has good activity against Streptococcus
A
Which statement about Piperacillin-Tazobactam is FALSE?
A. Has coverage for anaerobic organisms
B. It has good activity against Streptococcus
C. It can be used for MRSA Infections
D. It is effective against Klebsiella pneumoniae sepsis
C
Penicillins of choice for meningitis
Penicillin, ampicillin
Penicillin of choice for leptospira
Pen G
Penicillin of choice for Pseudomonas
Piperacillin
Penicillin of choice for anthrax
Pen G
Penicillin of choice for typhoid fever
Aminopenicillins
Penicillin of choice for E. coli
None
Penicillin of choice for MRSE
None
Penicillin of choice for MRSA
None
Other name for Pen G
Benzine Penicillin
Other name for Pen V
Phenoxymethylpenicillin
Other name for Benzine Penicillin
Pen G
Other name for Phenoxymethylpenicillin
Pen V
Preferred route for Pen G
IV
IM causes pain at injected site.
Usual beta-lactamase inhibitor partner of Amoxicillin
Clavulanic acid
Usual beta-lactamase inhibitor partner of Piperacillin
Tazobactam
Usual beta-lactamase inhibitor partner of Ticarcillin
Clavulanic acid
Usual beta-lactamase antibiotic partner of Tazobactam
Piperacillin
Usual betalactamase antibiotic partner of Clavulanic acid
Amoxicillin or Ticarciilin
Oral penicillins must be given how many hours before or after meals?
1-2
Which oral penicillin can be given with food?
Amoxicillin
Which drug is simultaneously administered with penicillins to raise penicillin blood levels?
Probenecid
Mechanism of action of probenecid to raise penicillin blood levels
Inhibits tubular secretion
Which penicillins have biliary secretion?
Nafcillin, oxacillin, cloxacillin, dicloxacillin
Mechanism of action of penicillins
Binds to the active site of PBP to inhibit transpeptidation in peptidoglycan synthesis
Penicillin resistance is most commonly through which mechanism?
Inactivation by beta-lactamase
What is the MRSA mechanism of resistance?
Modification of PBPs
Identify generation: Cefepime
4th
Identify generation: Cephalexin
1st
Identify generation: Cefazolin
1st
Identify generation: Cefuroxime
2nd
Identify generation: Ceftriaxone
3rd
Identify generation: Cefaclor
2nd
Identify generation: Cefixime
3rd
Identify generation: Ceftazidime
3rd
Identify generation: Cefoperazone
3rd
Identify generation: Cefotaxime
3rd
The only 3nd gen cephalosporins with adequate activity against Pseudomonas
Ceftazidime and Cefoperazone
Cephalosporins against Pseudomonas
Ceftazidime, Cefoperazone, Cefepime
Which cephalosporin generations have adequate activity against Pseudomonas?
3rd and fourth
Which cephalosporin has biliary excretion?
Ceftriaxone
Which cephalosporins can be used against meningitis?
Ceftriaxone and Cefotaxime
Of which generation are the cephalosporins used for meningitis?
3rd
Which cephalosporin can cause biliary sludge?
Ceftriaxone
Drugs which are eliminated unchanged by the kidneys include the following
a. Cefoxitin
b. Gentamicin
c. Streptomycin
d. AOTA
A. Cefoxitin is a cephalosphorin antibitotic that is excreted approximately 85% unchanged. Aminoglycosides such as gentamicin and streptomycin undergo renal excretion through glomerular filtration which may cause nephrotoxicity.
Which of the ff drugs can suppress linear growth of children?
a. Tetracycline
b. Corticosteroids
c. Ciprofloxacin
d. Zidovudine
B. Tetracycline affects teeth development and ciprofloxacin causes cartilage toxicity/arthroplasties. Maternal zidovudine intake decreases HIV transmission to fetus.
The following are all beta-lactamase inhibitors EXCEPT: A. Clavulanic acid B. Aztreonam C. Tazobactam D. Sulbactam
B
Antimicrobials which bind to the 30s ribosomal unit are the following EXCEPT: A. Doxycycline B. Amikacin C. Erythromycin D. Tetracycline
C
True of chloramphenicol:
A. may be given for bacterial pharyngitis
B. narrow spectrum antibiotic
C. bactericidal for H. influenzae, N. meningitides and S. pneumoniae
D. contraindicated in typhoid fever
C
Erythromycin may be used for the following indications EXCEPT: A. Legionella B. Ureaplasma urethritis C. Candida albicans D. Diphtheria
D
Which drug can cause vestibular toxicity? A. Levofloxacin B. Cefoperazone C. Amikacin D. Clarithromycin
C
The following are principles to follow in choosing the correct antibiotic for specific patients. Which statement is FALSE?
A. The physician should use an appropriate antibiotic with the broadest spectrum of activity.
B. The physician should collect appropriate specimens for diagnosis prior to starting antimicrobial therapy.
C. Physicians should only use new antibiotics if it holds clear advantages over existing therapies
D. Therapy should be directed against the most likely therapy which depends on the site of infection, age of the patient, immune status and antibiotic resistance pattern of the community
A
Match the antimicrobial with the advwese effect which it may produce: Levofloxacin
Aplastic anemia Damage to cartilge Seizures Dental hypoplasia Red man syndrome Biliary sludging
Damage to cartilage
Match the antimicrobial with the advwese effect which it may produce: Doxycycline
Aplastic anemia Damage to cartilge Seizures Dental hypoplasia Red man syndrome Biliary sludging
Dental hypoplasia
Match the antimicrobial with the advwese effect which it may produce: Chloramphenicol
Aplastic anemia Damage to cartilge Seizures Dental hypoplasia Red man syndrome Biliary sludging
Aplastic anemia
Match the antimicrobial with the advwese effect which it may produce: Imipenem
Aplastic anemia Damage to cartilge Seizures Dental hypoplasia Red man syndrome Biliary sludging
Seizures
Match the antimicrobial with the advwese effect which it may produce: Vancomycin
Aplastic anemia Damage to cartilge Seizures Dental hypoplasia Red man syndrome Biliary sludging
Red man syndrome
Match the antimicrobial with the advwese effect which it may produce: Ceftriaxone Aplastic anemia Damage to cartilge Seizures Dental hypoplasia Red man syndrome Biliary sludging
Biliary sludging
