Antibiotics - Principles Flashcards

1
Q

What % of UK inpatients are estimated to be taking antibiotics at any one time?

1 - 13%
2 - 23%
3 - 33%
4 - 66%

A

3 - 33%

  • aprox 1/3 of people in UK take an antibiotic course once a year
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2
Q

What is an empirical antibiotic?

1 - newest form of antibiotic
2 - prescribing of antibiotics on clinical knowledge only
3 - prescribing antibiotics when organism is unknown, but modified following culture
4 - prescribing antibiotics based on local guidelines only

A

3 - prescribing antibiotics when organism is unknown, but modified following culture

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3
Q

Is it important to take a culture prior to antibiotic prescribing?

A
  • yes
  • empirical antibiotics could affect culture results
  • BUT DO NOT DELAY IF NEEDED URGENTLY
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4
Q

If a RED FLAG , such as sepsis, septic shock or life threatening infection are identified, how urgently should we start antibiotics (most likely empirical as the cause is not always known)?

1 - <1h
2 - <4h
3 - <24h
4 - <48h

A

1 - <1h

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5
Q

When prescribing antibiotics, which of the following must be performed?

1 - indication for treatment
2 - severity of infection
3 - dose, route and frequency
4 - review and stop date and consider switch from IV to oral
5 - check microbiology results daily
6 - all of the above

A

6 - all of the above

  • MUST be in both the patient notes and prescription
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6
Q

At 48-72 hours we should generally review the patient and document a management plan including the next review or stopping the antibiotics. Why is this done at 48-72 hours?

1 - standard time for review
2 - most cultures are back within this period
3 - busy in hospitals
4 -doctors round every 48-72 hours

A

2 - most cultures are back within this period

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7
Q

Which of the following are examples of de-escalation in antibiotics (Abx)?

1 - stop Abs if no infection
2 - switch from IV to oral
3 - change Abx based on cultures
4 - continue IV if patient is unstable
5 - discharge on outpatient parental Abx if patient is infected but otherwise well
6 - all of the above

A

6 - all of the above

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8
Q

Which of the following is NOT a risk factors for antimicrobial resistance in hospitals?

1 - previous admission
2 - older age
3 - prolonged stay
4 - ICU admission
5 - poor hygiene
6 - invasive procedure

A

2 - older age

  • this is a patient risk factor
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9
Q

Which of the following is NOT a risk factors for antimicrobial resistance in patients?

1 - low socioeconomic
2 - immigrant status
3 - ICU admission
4 - older age
5 - comorbidities
6 - antibiotic overuse

A

3 - ICU admission

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10
Q

Which if the following is NOT classed as a superbug?

1 - Escherichia coli
2 - methicillin resistant staphylococcus aureus (MRSA)
3 - Clostridium difficile
4 - Vancomycin / Glycopeptide resistant enterococci (VRE / GRE)
5 - Extended spectrum B-lactamased (ESBLs)
6 - carbapenemase producers

A

1 - Escherichia coli

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11
Q

Methicillin resistant staphylococcus aureus (MRSA) is classed as a superbug. What change in MRSA makes it a superbug?

1 - increased B-lactamse concentrations
2 - no more peptides in cell wall
3 - evolved with mecA gene and modified cell wall binding protein 2a
4 - no longer contains a cell wall

A

3 - evolved with mecA gene and modified cell wall binding protein 2a

  • mecA gene makes proteins in peptide wall
  • new proteins (binding protein 2a) that are difficult for antibiotics to bind with
  • mecA gene also codes for B-lactamse enzyme that can degrade antibiotics
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12
Q

Methicillin resistant staphylococcus aureus (MRSA) is classed as a superbug, and tends to be linked with medical devices.

This is because MRSA has evolved with mecA gene, modifying its cell wall binding protein 2a. Which 2 antibiotics do show some effectiveness in treating MRSA?

1 - vancomyosin
2 - gentamicin
3 - linezolid
4 - cephalexi

A

1 - vancomyosin
3 - linezolid

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13
Q

Vancomycin / Glycopeptide resistant enterococci (VRE / GRE) are both classed as superbugs due to their resistance to antibiotics. What changes have occurred leading to these becoming superbugs?

1 - increased B-lactamse concentrations
2 - no more peptides in cell wall
3 - evolved with mecA gene
4 - modified cell wall

A

4 - modified cell wall

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14
Q

Vancomycin / Glycopeptide resistant enterococci (VRE / GRE) are both classed as superbugs due to their resistance to antibiotics, due to changes in the peptidoglycan cell walls. What antibiotics should some potential in treating these?

1 - vancomyosin
2 - gentamicin
3 - linezolid
4 - daptomycin

A

3 - linezolid
4 - daptomycin

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15
Q

Extended spectrum B-lactamased (ESBLs) are organisms classed as superbugs due to their antibiotic resistance. What changes have occurred leading to these becoming superbugs?

1 - increased B-lactamse concentrations
2 -able to inhibit enzymes
3 - evolved with mecA gene
4 - modified cell wall

A

2 - able to inhibit enzymes

  • resistant to most B-lactamases
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16
Q

Extended spectrum B-lactamased (ESBLs) are organisms classed as superbugs due to their antibiotic resistance as they are able to inhibit enzymes. What drugs are used to try and treat these?

1 - carbapenem
2 - gentamicin
3 - amikacin
4 - daptomycin

A

1 - carbapenem
3 - amikacin

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17
Q

We need to be sure that adequate levels of the antibiotics are able to reach the site of infection. One barrier is capillaires, such as in the brain. Which of the following are factors that can affect how much antibiotic reaches the site of infection?

1 - lipid solubility
2 - molecular weight
3 - protein binding
4 - susceptibility to transport/efflux pumps
5 - all of the above

A

5 - all of the above

18
Q

It is crucial to always ask about drug allergies in any setting as anaphylaxis can be fatal. What % of patients are estimated to be allergic to penicillin?

1 - 1%
2 - 10%
3 - 25%
4 - 50%

A

2 - 10%

19
Q

A 38 year old woman presents with a 1 day history of rigors, back pain and vomiting. Prior to this she had a 2 day history of dysuria. She has a past medical history of recurrent cystitis.
On examination she is dehydrated, febrile, tachycardic, normotensive and has loin and suprapubic pain.
Urinalysis reveals, positive for leukocytes, blood, and nitrites
You plan to admit her for fluid resuscitation and antibiotic treatment with a suspected diagnosis of acute pyelonephritis. All of the following can cause the patients presenting symptoms, but which of the following is most likely to be responsible for this presentation?

1 - Escherichia coli
2 - Klebsiella species
3 - Prteus mirablis
4 - Pseudomonasspecies
5 - Enterobacterspecies

A

1 - Escherichia coli

  • Escherichia coli(60-80% of uncomplicated infections).
  • Klebsiella species(20%).
  • Proteus mirablis(15%).
  • Pseudomonasspecies.
  • Enterobacterspecies.
20
Q

All of the following affect antibiotic prescribing decision, EXCEPT which one?

1 - Patient factors
2 - Gender
3 - Immune system
4 - Renal and hepatic function
5 - Perfusion
6 - Age
7 - Pregnancy

A
21
Q

In a patient with acute pyelonephritis, rank the following antibiotics in order of 1st line to 3rd line choice:

1 - Ciprofloxacin (Quinolones) (consider safety issues)
2 - Cefalexin (Cephalosporins)
3 - Co‑amoxiclav(only if culture results available and susceptible)

A

2 - Cefalexin (Cephalosporins)
3 - Co‑amoxiclav(only if culture results available and susceptible)
1 - Ciprofloxacin (Quinolones) (consider safety issues)

22
Q

In a patient with acute pyelonephritis, rank the following antibiotics in order of 1st line to 3rd line choice in someone who is unable to have oral antibiotics and needs antibiotics via IV?

1 - Ceftriaxone (Cephalosporins)
2 - Cefuroxime (Cephalosporins)
3 - Co‑amoxiclav(only in combination and if culture results available and susceptible)

A

3 - Co‑amoxiclav(only in combination and if culture results available and susceptible)
2 - Cefuroxime (Cephalosporins)
1 - Ceftriaxone (Cephalosporins)

23
Q

Which 2 of the following are the antibiotic of choice in a patient who is breastfeeding?

1 - Cephalosporins
2 - Penicillins
3 - Tetracyclines
4 - Macrolides

A

1 - Cephalosporins
2 - Penicillins

  • trace amounts have been found in breast milk though
24
Q

A50-year-old man was admitted to hospital with a painful right leg. Hehad been feeling feverish and generally unwell for the past 3 days. His past medical history included pulmonary tuberculosis and a recent hospital admission with pneumonia. Hewas nottaking any regular medications. Hedrank approximately 30units of alcohol per week and smoked 20cigarettes daily. On examination, he was noted to be febrile and to have a hot, swollen, erythematous right leg. Thepatient was diagnosed with a right lower limb cellulitis.

What organisms are likely to be responsible for this presentation?

1 - Streptococcus pyogenes andStaphylococcus aureus
2 - Streptococcus pneumoniae,
3 - Haemophilus influenzae
4 - gram-negative bacilli and anaerobes

A

1 - Streptococcus pyogenes andStaphylococcus aureus

  • all of these organisms can cause this, but these are the most likely
25
Q

In a patient with cellulitis that is deemed non severe, the antibiotic of choice should be oral. Which of the following should be 1st choice?

1 - Flucloxacillin (Penicillin)
2 - Clarithromycin (Macrolides)
3 - Erythromycin(Macrolides)
4 - Doxycycline(Tetracycline)

A

1 - Flucloxacillin (Penicillin)

  • alternative first-choice antibiotics for penicillin allergy or if flucloxacillin is unsuitable(give orally unless person unable to take oral or severely unwell)
  • other antibiotics here are the alternatives
26
Q

Which of the following antibiotic agents should not be given to children less than 8years of age due to its deposition in bone and teeth?

A. Clarithromycin
B. Doxycycline
C. Vancomycin
D. Amoxicillin

A

B. Doxycycline
- Tetracyclines
- contraindicated in this age group because they are deposited in tissues undergoing calcification, such as teeth and bone, and can stunt growth.

27
Q

A 21-year-old marathon runner reports to the clinic with acute Achilles tendon rupture. The nurse noted that the patient recently took an antibiotic. Which of the following antibiotics may have contributed to tendon rupture?A. Amoxicillin/clavulanic acid
B. Cefalexin
C. Ciprofloxacin
D. Minocycline

A

C. Quinolones (ciprofloxacin)
- associated with tendon ruptures and tendinopathy. The other agents are not associated with this adverse effect

28
Q

Which of the following does NOT cause community acquired pneumonia (CAP)?

1 - Streptococcus pneumoniae
2 - Haemophilus influenzae
3 - Klebsiella pneumoniae
4 - S. aureus
5 - Escherichia coli
6 - Atypical organisms
7 - Viral (up to 13%)

A

5 - Escherichia coli

  • Streptococcus pneumonia is the most common cause
29
Q

If we suspect community acquired pneumonia (CAP), which of the following is NOT

1 - chest x-ray
2 - whole body CT
3 - serum and urine for pneumococcal and legionella testing if atypical features
4 - sputum sample
5 - sputum / throat swab for viral culture and immunofluorescence

A

2 - whole body CT

30
Q

The 65 in the CURB-65 score is for people >65 year of age. What does the C stand for in CURB-65 score?

1 - continuous oxygen needed
2 - confusion (new onset)
3 - CPAP indicated
4 - capillary refill time

A

2 - confusion (new onset)

  • AMT = Abbreviated Mental Test
  • AMT <8
31
Q

The 65 in the CURB-65 score is for people >65 year of age. What does the U stand for in CURB-65 score?

1 - urea
2 - urine output
3 - urobilligen levels
4 - ureter blockage

A

1 - urea

  • > 7mmol/L
  • normal = 2.5 - 7.8 mmol/L
32
Q

The 65 in the CURB-65 score is for people >65 year of age. What does the R stand for in CURB-65 score?

1 - reactions
2 - reflexes
3 - renal output
4 - respiratory rate

A

4 - respiratory rate

  • ≥ 30/min
33
Q

The 65 in the CURB-65 score is for people >65 year of age. What does the B stand for in CURB-65 score?

1 - bilateral breath sounds
2 - bells palsy
3 - blood pressure
4 - baroreceptor response

A

3 - blood pressure

  • SBP <90mmHg or DBP ≤60mmHg
34
Q

87 year old male, weight 80kg
Presenting complaint: Cough, SOB, temperature. Feeling generally unwell.
PMHx: COPD, AF, ↑ cholesterol, GORD
DHx: NKDA

  • Trelegy Ellipta inhaler 92/55/22mcg 1 puff inhaled OD (Fluticasone (Glucocorticoids)/Umeclidinium bromide (LAMA)/Vilanterol (LABA))
  • Apixaban 5mg po BD
  • Lansoprazole (PPI) 30mg po OD
  • Simvastatin po 40mg
  • Salbutamol inhaler PRN

Of the drugs listed here, the 2 core macrolide antibiotics (Clarithromycin, Erythromycin) both inhibit cytochrome P450 (CYP). Which of the patients drugs above would be affected by CYP inhibition and result in adverse events?

1 - Apixaban
2 - Lansoprazole
3 - Simvastatin
4 - Salbutamol

A

3 - Simvastatin

  • simvastin is metabolised by CYP
  • inhibition of CYP increases simvastin levels
  • increased simvastatin levels could cause adverse events should as rhabdomyolysis
35
Q

87 year old male, weight 80kg
Presenting complaint: Cough, SOB, temperature. Feeling generally unwell.
PMHx: COPD, AF, ↑ cholesterol, GORD
DHx: NKDA. What woukld this patients CURB-65 score be with the following:

  • WCC 13.5 (4-11*109/L)
  • CRP 51.9 (0-5mg/L)
  • HR =91
  • Temp = 36.7oC
  • SpO2 = 93% on air,
  • Cr 80 (59-104micromol/L)
  • Urea 12.5 (2.5-7.8mmol/L)
  • BP 88/69mmHg
  • RR 22.
  • No confusion

1 - 2
2 - 3
3 - 4
4 - 5

A

1 - 2

  • 1 point for >65 y/o
  • 1 point for raised urea

– maximum possible score is 5

36
Q

87 year old male, weight 80kg
Presenting complaint: Cough, SOB, temperature. Feeling generally unwell.
PMHx: COPD, AF, ↑ cholesterol, GORD
DHx: NKDA

  • Trelegy Ellipta inhaler 92/55/22mcg 1 puff inhaled OD (Fluticasone (Glucocorticoids)/Umeclidinium bromide (LAMA)/Vilanterol (LABA))
  • Apixaban 5mg po BD
  • Lansoprazole (PPI) 30mg po OD
  • Simvastatin po 40mg
  • Salbutamol inhaler PRN

This patient has a CURB-65 score of 2, what antibiotic should a patient be prescribed?

1 - amoxicillin
2 - clarithromycin
3 - erythromycin
4 - doxycycline

A

1 - amoxicillin

  • 1st choice antibiotic
  • clarithromycin and erythromycin are both Macrolides that inhibit cytochrome P450 (CYP)
  • simvastatin is metabolised by CYP, if CYP is inhibited it increased adverse events such as rhabdomyolysis
  • doxycycline is 2nd line if penicillin allergy
37
Q

In a patient with the following: 82yr old male, 5ft 3in, 94kg, what would the ideal body weight (IBW) be?

1 - 43.1kg
2 - 52.3kg
3 - 54.6kg
4 - 59.6kg

A

4 - 59.6kg

  • IBW formula
    males = 50kg + (2.3 x inches >5ft)
    females - 45.5kg + (2.3 x inches >5ft)
  • 50 + (2.3 x 3 = 6.9) = 56.9kg
38
Q

In a patient with the following: 82yr old male, 5ft 3in, 94kg and an ideal body weight (IBW) of 56.9kg, what is the extra body weight (EBW)?

1 - 37.1kg
2 - 45.92kg
3 - 96kg
4 - 37.1kg

A

1 - 37.1kg

  • 94kg - 56.9kg = 37.1kg
39
Q

In a patient with the following: 82yr old male, 5ft 3in, 94kg, an ideal body weight (IBW) of 56.9kg, an extra body weight (EBW) of 37.1kg, what is the corrected body weight (CBW)?

1 - 45.52kg
2 - 45.92kg
3 - 71.74kg
4 - 37.1kg

A

3 - 71.74kg
- 72kg

  • 56.9 + (0.4 x 37.1) = 71.74kg
40
Q

In a patient with the following: 82yr old male, 5ft 3in, 94kg, an ideal body weight (IBW) of 56.9kg, an extra body weight (EBW) of 37.1kg, a corrected body weight (CBW) 72kg and a creatine of 148, calculate the renal function using the formula below:

MALE
CrCl = 1.23 x (140-age) x Ideal Body Weight (kg)
Serum Creatinine
FEMALE
CrCl = 1.04 x (140-age) x Ideal Body Weight (kg)
Serum Creatinine

1 - 27.43
2 - 23.19
3 - 17.88
4 - 31.23

A

1 - 27.43

  • 1.23 x (140 - 82) x 56.9/148 = 27.43
41
Q

The gentamicin dosage is based on corrected body weight (CBW) and creatine clearance (CrCl). The patient has the following:

  • 82yr old male, 5ft 3in, 94kg
  • ideal body weight (IBW) of 56.9kg
  • extra body weight (EBW) of 37.1kg
  • corrected body weight (CBW) 72kg
  • creatine of 148,

What is the gentamicin dosage for this patient if the dosage is 5mg/kg (CrCl >30) and 3mg/kg (<CrCl <30)

1 - 360mg
2 - 28mg
3 - 216mg
4 - 190mg

A

3 - 216mg

  • 3 x 72 - 216
  • round up to 220mg OD