Week 7

Question 1

What class of antibiotics are responsible for causing discoloration and hypoplasia of teeth and bone?

Answer 1

tetracyclines

Question 1

What class of antibiotics are responsible for preventing binding of tRNA to the mRNA by binding to the 30S subunit?

Answer 1

tetracyclines

Question 2

This type of antibiotic is slowly degraded into nephrotoxic compounds in the container, so they shouldn’t be given to patients if over 6 months old.

Answer 2

tetracyclines

Question 3

Which antibiotic was developed to combat resistant to tetracyclines?

Answer 3

Glycylcycline (Tigecycline)

Question 4

Which class of antibiotics bind to the 30S ribosome subunit and distort its structure causing misreading of the mRNA?

Answer 4

aminoglycosides

Question 5

What are some major side effects of aminoglycosides?

Answer 5

Ototoxicity (may be irreversible), nephrotoxicity, neuromuscular paralysis

Question 6

Which class of antibiotics bind to the 50S subunit of ribosome and inhibits translocation steps of protein synthesis?

Answer 6

Macrolides

Question 7

Which class of antibiotics is known for its drug-drug interactions with inhibition of CYP3A4 (grape juice)?

Answer 7

Macrolides

Question 8

Which class of antibiotics is similar to macrolides, but its MOA is inhibiting RNA synthesis by RNA polymerases?

Answer 8

Macrocyclics (Fidaxomicin)

Question 9

Which class of antibiotics is similar to macrolides and binds to 50S ribosome subunit and inhibits protein synthesis by blocking the polypeptide exit tunnel?

Answer 9

Lincosamides (clindamycin)

Question 10

Which class of antibiotics bind to the bacterial 23S ribosomal RNA of the 50S subunit which inhibits the formation of the 70S initiation complex and translation of bacterial proteins?

Answer 10

Oxazolidinones (linezolid, tedizolid)

Question 11

Which class of antibiotics inhibits both A & B subtypes of monoamine oxidase?

Answer 11

Oxazolidinones (linezolid, tedizolid)

Question 12

Which class of antibiotics disrupts elongation and typically used in combination?

Answer 12

Streptogramins (dalfopristin/quinupristin)

Question 13

Which class of antibiotics attacks the 50S ribosomal subunit and inhibits protein synthesis at the peptidyl transferase reaction?

Answer 13

Chloramphenicol

Question 14

Which form of penicillin is orally administered and more stable in acidic conditions?

Answer 14

Penicillin V

Penicillin V is the oral form of penicillin and is more stable in acidic conditions. It is typically used for minor infections due to its poor bioavailability, narrow spectrum, and requirement of multiple daily dosing.

Question 15

Which antibiotic is the standard therapy for primary, secondary, or early latent syphilis?

Answer 15

Penicillin G

A single dose of benzathine penicillin G is the standard therapy for primary, secondary, or early latent syphilis caused by the spirochete Treponema pallidum, providing low but persistent serum levels of penicillin.

Question 16

What is the most common mechanism of antibiotic resistance in penicillin?

Answer 16

The most common mechanism of antibiotic resistance in penicillin is the production of beta-lactamases by bacteria, such as Staphylococcus aureus. These enzymes degrade the beta-lactam ring of penicillin, rendering them ineffective.

Question 17

Which molecular structure makes the antibiotics nafcillin, oxacillin, methicillin, and dicloxacillin resistant to cleavage by bacterial beta-lactamases?

Answer 17

bulky R group

Question 18

What are the antistaphylococcal penicillins?

Answer 18

Oxacillin, Nafcillin, Dicloxacillin (Methicillin)

Question 19

Why are anti-staphylococcal penicillins not effective against MRSA?

Answer 19

Methicillin-resistant Staphylococcus aureus (MRSA) produces altered penicillin binding proteins that have a low affinity for binding beta-lactam antibiotics. This renders anti-staphylococcal penicillins ineffective.

Question 20

For which bacterial infections is empiric treatment with nafcillin, oxacillin, or dicloxacillin most appropriate?

Answer 20

skin and soft tissue infections

Question 21

Which of the following best describes the mechanism of action shared by the tazobactam and sulbactam?

Answer 21

Tazobactam and sulbactam inhibit bacterial β-lactamases. These drugs protect penicillin antibiotics from destruction by β-lactamases, enabling penicillin-based therapy for bacteria such as methicillin-sensitive Staph aureus.

Question 22

When compared to other penicillins, piperacillin and ticarcillin have important additional indications due to activity against which of the following bacteria?

Answer 22

Pseudomonas species

Pseudomonas is a gram-negative aerobic bacteria that can cause a wide variety of serious infections, including pneumonia, urinary tract infection, and otitis externa. Piperacillin and ticarcillin are extended-spectrum penicillins, which unlike other penicillins, can be used to treat Pseudomonas infections.

Question 23

What is the difference between the pharmacokinetic properties of the amino-penicillins amoxicillin and ampicillin?

Answer 23

The amino-penicillins, amoxicillin and ampicillin, have similar spectrums of activity, but amoxicillin has better oral bioavailability; a mnemonic is that aMOxacillin is administered by MOuth, and AMPicillin comes in AMPules. Amoxicillin is often given orally for common pediatric illness, including infections of the ear, sinuses, or throat. On the other hand, ampicillin is administered intravenously for more serious infections that require anaerobic coverage such as aspiration pneumonia.

Question 24

Which of the following best describes the mechanism by which Enterococcus may become resistant to ampicillin?

Answer 24

Ampicillin-resistant strains of Enterococcus produce β-lactamase, which cleaves the β-lactam ring and prevents β-lactam antibiotics from blocking bacterial transpeptidase peptidoglycan cross-linking. Resistant Enterococcus infections may be treated with ampicillin plus sulbactam or with vancomycin.

Question 25

What is a distinguishing feature of cephalosporin antibiotics in comparison to the penicillin antibiotic ampicillin?

Answer 25

They are resistant to penicillinase, but vulnerable to other beta-lactamases Like ampicillin, cephalosporins are β-lactam antibiotics that bind penicillin binding protein (transpeptidase), preventing it from cross-linking peptidoglycan in the bacterial cell wall. However, while ampicillin is susceptible to β-lactamase (penicillinase), β-lactamases are ineffective against cephalosporins.

Question 26

Aztreonam is most effective in treating infections caused by which of following pathogens?

Answer 26

gram negative aerobics

Question 27

What is the primary treatment for Listeria monocytogenes?

Answer 27

Ampicillin

Question 28

Vancomycin is an important antibiotic used to treat gram _____ bacterial infections.

Answer 28

positive Vancomycin is often used as empiric treatment when methicillin-resistant Staphylococcus aureus (MRSA) is suspected. Vancomycin is not effective against gram negative organisms.

Question 29

What is the mechanism of action of vancomycin?

Answer 29

Vancomycin is a glycopeptide antibiotic which obstruct the synthesis of bacterial cell walls. Vancomycin binds to the cell wall precursors D-alanine-D-alanine. By binding to these oligopeptides, vancomycin inhibits the synthesis of peptidoglycan necessary to make up the cell wall.

Question 30

What is the difference between lipoglycopeptides and glycopeptide antibiotics?

Answer 30

lipoglycopeptides are more potent

Question 31

Imipenem is administered as a broad spectrum antibiotic but it is easily degraded by the kidneys. What is administered alongside to prevent this?

Answer 31

Cilastatin

Question 32

The lowest concentration of drug required to inhibit the growth of an organism.

Answer 32

Minimum inhibitory concentration

Question 33

Why do you need to use a loading dose?

Answer 33

for rapid onset and establishment above MIC levels

Question 34

This refers to the phenomenon where bacterial growth remains suppressed even after the concentration of an antibiotic has fallen below the minimum inhibitory concentration (MIC).

Answer 34

post-antibiotic effect

Question 35

Answer 35

Acrosomal rxn

Question 36

Fertilin and integrin are two molecular determinants involved in which process?

Answer 36

The fusion of sperm head and secondary oocyte membranes. It is also responsible for blocking polyspermy.

Question 37

Which structure secretes hCG and what is its function?

Answer 37

syncytium and it maintains the corpus luteum

Question 38

What happen to estrogen levels throughout pregancy?

Answer 38

Increases due to secretion of estrogen from placenta. Has roles in mammary gland development and myometrial growth (smooth muscle of the uterus)

Question 39

Which protein expressed by the cytotrophoblasts allows the mother's immune system to recognize the fetus as "self"?

Answer 39

HLA-G

Question 40

What is the role of progesterone secreted by the placenta?

Answer 40

decreases myometrial excitability, maintains cervical mucus plug, increases development of secretory milk glands

Question 41

What is the role of hCS?

Answer 41

like growth hormone

Question 42

Early in pregnancy which hormones are responsible for inhibiting myometrial contractility?

Answer 42

progesterone and relaxin

Question 43

Answer 43

Relaxin

Question 44

Which hormone secreted by the placenta acts as the "placental clock"

Answer 44

CRH

Question 45

Which hormones play an important role in the initiation and control of labor?

Answer 45

prostaglandins and leukotrienes

Question 46

Pregnant women may experience mild fasting hypoglycemia and postprandial hyperglycemia and hyperinsulinemia due to what?

Answer 46

peripheral insulin resistance (cause of gestational diabetes)

Question 47

What happens to LDL and HDL concentrations during pregnancy?

Answer 47

Increase due to effects of progesterone and estrogen, respectively

Question 48

The physical act of a baby suckling at the breast sends nerve signals to the hypothalamus. This inhibits the release of ____ (which normally inhibits prolactin), thereby increasing prolactin secretion.

Answer 48

dopamine

Question 49

This hormone is important for milk ejection and milk letdown. It can also be secreted due to other stimuli such as a crying baby

Answer 49

oxytocin

Question 50

What is the MOA for fluoroquinolones?

Answer 50

inhibits DNA synthesis specifically blocking activity of DNA gyrase

Question 51

What is the common suffix ending for the drugs which are part of the fluoroquinolone family?

Answer 51

-oxacin "flock-of-oxen"

Question 52

A patient being treated with fluoroquinolones for pneumonia is found to have an abnormal EKG. What is the most likely abnormality?

Answer 52

prolonged QT interval

Question 53

Fluoroquinolones should be given a few hours before or after the ingestion of:

Answer 53

dairy (bc calcium, iron, and aluminium interact)

Question 54

what is the mechanism of action for rifamycins

Answer 54

block RNA synthesis

Question 55

What is the most common therapeutic use for rifampins?

Answer 55

tuberculosis (always used in combo w/ other drugs)

Question 56

What is a major common side effect of rifampin use?

Answer 56

red/orange color to urine, sweat, tears

Question 57

Sulfamethoxazole and trimethoprim combo is used to treat what type of infections?

Answer 57

UTIs

Question 58

What is the MOA for Sulfamethoxazole and trimethoprim combo?

Answer 58

inhibits the tetrahydrofolic acid (THF) pathway

Question 59

Metronidazole is effective against anaerobic bacteria and certain protozoan infections, including Giardia. However, it is not effective against _____.

Answer 59

aerobes

Question 60

What is metronidazole's mechanism of action?

Answer 60

Disrupts bacterial DNA Metronidazole forms toxic free radical metabolites in the cell that disrupt bacterial DNA. This leads to bacterial cell death (metronidazole is bactericidal).

Question 61

Ingesting _____ while receiving metronidazole therapy can trigger a disulfiram-like reaction, characterized by flushing, palpitations, nausea, and vomiting.

Answer 61

alcohol

Question 62

What is the MOA for Mupirocin?

Answer 62

acts on gram-positive cocci and inhibits RNA and protein synthesis

Question 63

What is the therapeutic use for Mupirocin?

Answer 63

topical application for impetigo (school sores)

Question 64

What is Nitrofurantoin used to treat?

Answer 64

acute uncomplicated UTIs

Question 65

What is the MOA for methenamine?

Answer 65

Methenamine works by breaking down into formaldehyde in acidic urine, which then kills bacteria and helps prevent urinary tract infections.

Question 66

For a patient with chronic UTIs, what would you recommend medication wise?

Answer 66

methenamine

Question 67

A pregnant woman experiences constipation and bloating. Which hormone can you attribute this to and why?

Answer 67

progesterone because it slows peristalsis and gastric emptying

Question 68

Anemia is common in early pregnancy. Why is this and what should you recommend for the patient?

Answer 68

The body is starting to prepare for delivery and the possibility of blood loss. Hemoglobin levels don't increase right away. Recommend iron supplement.

Question 69

What pulmonary changes does a woman experience during pregnancy?

Answer 69

functional residual capacity/residual volume decreased due to uterus pushing up on diaphragm which pushes lungs

Question 70

You are listening for murmurs in a pregnant patient. You hear a systolic murmur. Is this a normal finding?

Answer 70

Yes. Diastolic murmurs are NEVER normal!

Question 71

Is lower back lordosis normal for a pregnant patient?

Answer 71

Yes, it is to accommodate the baby and to change center of gravity for balance.

Question 72

Vast majority of inborn errors of metabolism are inherited in a ____ manner.

Answer 72

recessive

Question 73

A biochemical test which measures enzyme activity in patient cells is considered a direct or indirect test?

Answer 73

direct

Question 74

A biochemical test which measures levels of metabolites in blood via tandem mass spectrometry (MS/MS) is considered a direct or indirect test?

Answer 74

indirect

Question 75

This indirect test allows for simultaneous identification of multiple compounds in a dried blood spot. It measures the products of enzyme activity in the circulation.

Answer 75

MS/MS

Question 76

____ is performed on asymptomatic people NOT seeking medical care

Answer 76

screening

Question 77

____ is performed in symptomatic people to establish or confirm a diagnosis

Answer 77

diagnostic testing

Question 78

_____ is performed on asymptomatic people that had a positive screen in order to confirm or refute the positive result

Answer 78

diagnostic testing

Question 79

What is the most common bacteria in the vagina and is it anaerobic and aerobic?

Answer 79

lactobacillus; gram-positive aerobic

Question 80

Lactobacilli produce these two compounds which help to inhibit pathogenic processes.

Answer 80

lactic acid and H2O2

Question 81

Name the condition in which there is an alteration in the composition of normal flora. Typically occurs when the anaerobic bacteria overtake the normal aerobic bacteria.

Answer 81

bacterial vaginosis

Question 82

Anaerobes are linked to an increased incidence of what?

Answer 82

HIV

Question 83

An increase in this bacteria is typically seen in bacterial vaginosis.

Answer 83

gardnerella vaginalis

Question 84

This fungus is a part of the normal vaginal flora but can overgrow if the normal flora experiences a disruption

Answer 84

candida albicans

Question 85

Fungal wall is made up of this compound.

Answer 85

chitin and ergosterol (cholesterol)

Question 86

This hormone in oral contraceptive increases the risk of DVT.

Answer 86

estrogen

Question 87

During 1st trimester, when trying to establish date of pregnancy using ultrasound, what is the most accurate measurement?

Answer 87

crown rump length

Question 88

Definition of labor

Answer 88

cervical changes and uterine contractions

Question 89

For a woman who has had a baby in the past, how long should she push until other measures should be taken?

Answer 89

<2 hours

Question 90

Spider angiomas and nasal congestion/nose bleeds during pregnancy is attributed to which hormone?

Answer 90

estrogen

Question 91

nausea and vomiting of pregnancy is attributed to which hormone?

Answer 91

hCG and estrogen