Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Finals Pharmacology old > t100 Antibiotics > Flashcards

t100 Antibiotics Flashcards

1
Q

name an aminoglycoside

A

gentamicin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

indications aminoglycosides

A

1) severe sepsis, inc where unidentified
2) pyleonephritis and complicated uti
3) biliary and intraabdo sepsis
4) endocarditis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

spectrum of action aminoglycosides

A

gram negative aerobes
staphylococci
mycobacteria

Does NOT cover
streptococci
anaerobic bacteria

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

mechanism of action aminoglycosides

A

Inhibit protein synthesis 30S

bind irreversibly to bacterial ribosome(30S subunit) and inhibit protein synthesis.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

when might aminoglycosides need to be combined with something else? what else?

A

combine with penicillin and/or metronidazole when organism unknown

(to cover streptococci and anaerobes)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

most important adverse effects aminoglycosides?

A

nephrotoxicity and ototoxicity

aminoglycosides accumulate in tubular epithelial cells and cochlear and vestibular cells where they trigger apoptosis and cell death

nephrotoxicity = reduced urine output, rising serum creatinine and is potentially reversible

ototoxicty = hearing loss, tinnitus (cochlear damage) vertigo (vestibular damage) after infection, may be irreversible

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

routes of administration aminoglycosides

A

only IV

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

How to reduce the risk of adverse effects aminoglycosides? contraindications?

A

Administartion:
- diluted and infuses slowly over 30 mins to prevent high concs which can damage the ear

Patient:
-neonates, elderly, renal impaired most at risk - calculate dose correctly and monitor serum closely
- myasthenia gravis avoid unless absolutely neccessary (impairs neuromuscualr transmission

Interactons:
- ototoxicity more likely if coprescribed wirh loop diuretics or vancomycin
- nephrotoxicity more likely if co-prescribed with ciclosporin, platinum chemo, cephalosporins and vancomycin

Monitoring:
- renally excreted, monitor plasma drug concentartions with dose adjustment to prevent complications

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

name 2 cephalosporins and 1 carbepenem

A
  • cefalexin
  • cefotaxime
  • meropenem
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

indications cephalosporins and carbepenems?

A
  • oral cephalosporins are 2nd/3rd line option for urinary and respiratory tract infections
  • IV cephalosporins and carbepenems are reserved for infections that are very severe or complicated or caused by resistant organisms
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

spectrum of action cephalosporins and carbapenems

A

broad spectrum
gram +/-

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

MoA cephalosporins and carbapenems?

A

B-lactam ring
Inhibit cell wall synthesis

inhibit enzymes responsible for cross linking petidoglycans in bacterial cell walls –> weakens cellw all –> cant maintain osmotic gradient –> bacterial swelling, lysis, death

more resistant ro b-lactamases than penicillins due to fusion of b-lactam ring with dihydrothiazine ring or uniqe side chain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

adverse effects cephalosporins and cabapenems?

A

common: GI upset N&V

uncommon: c.diff

hypersensitivity including immediate and delayed reactions may occur (CARBAPENEMS - CAUTION IN PEN-ALLERGIC PATIENTS) cephalosporins are fine in pen allergy

CNS toxicity inc seizures with carbapenems (reduces seizure threshold) esp patients taking high dose or pts with renal impairment

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

routes of administration cephalosporins and carbepenems?

A

cephalosporins oral (eg cefalexin), tablets, capsulesm oral suspensipn OR injection IV, bolus, infusion or IM

carbapenems only IV injection or infusion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

How to reduce risk of adverse effects cephalosporins and carbapenems?

A

Patient:
- CHECK NOT ALLERGIC TO OTHER B-LACTAM ABX
- use with caution in pts at risk of c,diff
- use caution in epilepsy
- dose reduction in renal impairment

Interactions:
- enhances anticoagulant effect of warfarin (INR increases)
- increase nephrotoxicuty of aminoglycosides
- reduces plasma conc and efficacy of valproate

Monitoring:
- symptoms and inflammatory markers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Name 3 macrolides

A

clarithromycin
azithromycin
erythromycin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

indications macrolides

A
  • resp and soft tissue as an alternative to penicilin when this is contraindicated by allergy
  • in severe pneumonia added to a penicillin to cover atypical organisms
  • eradication of h.pylori (with amox/metro and PPI)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

spectrum of action macrolides

A

broad spectrum
better for gram +
atypical

synthetic eg clarith and azith have increased acitivity against gram negative comapred to eryth

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

MoA macrolides

A

Inhibit protein synthesis (50S)

bind to 50S ribosome subunit

inhibit bacterial protein synthesis and blocks translocation ‘bacteriostatic’ - stops bacterial growth - assist immune system in removing them

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

adverse effects macrolides?

A

adverse effects most common and severe with erythromycin

  • irritant : N&V, abdo pain, diarrhoea
  • thrombophlebitis when given IV
  • allergy (but not related at all to penicillins)
  • antibiotic-associated colitis
  • liver abnormalities inc choleststic jaundice
  • prolongation of QT interval
  • ototoxicity in high doses = tinnitus
  • E and C inhibit cytochrome P450 therefore increases plasma conc of drugs such as warfarin and statins .
  • prescribe with caution in patients taking drugs that prolong the QT interval or cause arryth such as amiadarone, antipsychitics, quinine, quinolone abx, SSRIs
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

metabolism of macrolides

A

mostly hepatic with some renal contribution

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

how to reduce adverse effects macrolides

A

patient:
- dont prescribe if history of hypersensitivity
- caution in hepatic impairment
- dose reduction in severe renal impairment

Interactions:
- E and C inhibit cytochrome P450 therefore increases plasma conc of drugs such as warfarin and statins .
- prescribe with caution in patients taking drugs that prolong the QT interval or cause arryth such as amiadarone, antipsychitics, quinine, quinolone abx, SSRIs

Monitoring:
- symptoms, examination, inflammatory markers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

routes of administration macrolides

A

oral or IV infusion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

most commonly prescribed macrolide, why?

A

clarithromycin

fewer SE than erythromycin
cheaper than azithromycin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
name 1 nitroimidazole abx
metronidazole
26
Indications metronidazole
- antibiotic associated colitis caused by c.diff - oral infections (such as dental abscess) or aspiration pneumonia caused by gram negative anaerobes from the mouth
27
spectrum of action metronidazole
anaerobic bacteria protozoa eg trichomonas, amoebic dystentry, giardia
28
MoA metronidazole
inhibit protein synthesis by disrupting the DNA of the susceptible bacteria and inhibiting the protein synthesis of the cell wall leading to cell death;
29
adverse effects metronidazole?
Drug: - GI upset - immediate and delayed hypersensitivity - if prolonged: peripheral and optic neuropathy, encephalopathy, seizures Patient: - dose reduce in liver disease Interactions: - inhibits acetylaldehyde dehydrogenase which clears alcohol metabolite so cannot drink on metro - will cause disulfiram-like reaction - inhibits p450 so reduces metabolism of drugs such as warfarin and phenytoin - p450 enzyme inducers such as phenytoin and rifampicin can reduce plasma conc of metro and reduce antimicrobial efficacy
30
routes of administartion metronidazole
oral IV rectal topical gel
31
name 1 nitrofuran antibiotic
nitrofurantoin
32
indications nitrofurantoin
- first line antibiotic fro uncomplicated lower urinary tract infections
33
spectrum of coverage nitrofurantoin
works against the gram negative (e.coli) and gram positive (staphlococcus sapriphyticus) organisms that commonly cuase UTI klebisella has intrinsic resistance to nitrofurantoin
34
adverse effects nitrofurantoin
- GI upset - immediate and delayed hypersensitivity - yellow/brown urine - inflammation and fibrosis of lung - hepatitis - peripheral neuripathy - haemolytic anaemia in neonates - haemolytic anaemia in neonates if given towards term to pregnant mother
35
how to reduce adverse effects of nitrofurantoin
Contraindications - pregnant women towards tern - babies <3 mo - renal impairment - caution for long term prevention of UTI as increases risk of adverse effects - take with food/milk to reduce GI upset
36
name 2 basic penicillins
benzylpenicillin phenoxymethylpneicilllin (pen v)
37
indications basic penicillins
1. strep infection including tonsilitis, pneumonia, endocarditis, skina dn soft tissue (added to fluclox if severe) 2. clostridial infection eg tetanus 3. meningococcal infection eg meningitis, spetacaemia
38
spectrum of coverage basic penicillins
broad spectrum but resistance can develop easily
39
adverse effects all penicillins
general - allergy causing skin rash (subacute IgG delayed) - allergy causing anaphylaxis (acute IgE) patient - CNS toxicity in renal impairment - dose reduction - reduces renal excretion of methotrexate
40
routes of administartion basic penicillin
benzylpenicillin - IV or IM pen V oral or oral solution
41
what abx is a penicillin that is antipseudomonal
piperacillin with tazobactam (tazocin)
42
MoA penicillins
inhibit cell wall synthesis B lactam
43
Indications antipseudonomal penicillins
severe infections where there is ?broad spectrum poetntial pathogens and antibiotic resistance is likley eg hospital acquired, immunocompromise 1. LRTI 2. UTI 3. Intra-abdo sepsis 4. skin and soft tissue
44
what is tazobactam, how does it work
B lactamase inhibitor gives activity against b-lactamase producing bacteria eg staph aureus, gram negative anaerobes
45
what is piperacillin, how does it work
penicillin with side chain urea to give activity against pseudonomas aerginosa
46
route of administartion tazocin
IV
47
name 2 broad spectrum abx
amoxicillin co-amoxiclav
48
indications for broad spectrum abx
1. pneumonia 2. UTI 3. co-amoxiclav for hospital-aquired infection or intra-abdo sepsis which may be caused by gram negative and anaerobic and antibiotic resistant organisms 4. as part of h.pylori treatment
49
why is amoxicillin considered broad spectrum
side chain amino group gives activity against aerobic gram negative bacteria
50
what is clauvinic acid?
added to amoxicillin to create co-amoxiclav b-lactamase inhibitor - increases avitivity to staph aureus and gram neagtive anaerobes
51
routes of administartion broad spectrum penicillins
oral and IV
52
name penicillinase resistant penicillin
flucloxacilin
53
indications flucloxacillin
1. skin and soft tissue such as cellulitis 2. osteomyelitis and septic arthritis 3. other infections such as endocarditis
54
action of flucloxacillin
normal penicllin but side chain means effective against b lactamase producing staphlococci
55
how is MRSA resistant?
reduces penicillin binding affinity
56
what is MRSA
MRSA refers to staphylococcus aureus bacteria that have become resistant to beta-lactam antibiotics such as penicillins, cephalosporins and carbapenems.
57
how is MRSA treated
Eradication usually involves a combination of chlorhexidine body washes and antibacterial nasal creams. Antibiotic treatment options for MRSA are: Doxycycline Clindamycin Vancomycin Teicoplanin Linezolid
58
what are extended spectrum beta lactamase bacteria?
ESBLs are bacteria that have developed resistance to beta-lactam antibiotics. They produce beta lactamase enzymes that destroy the beta-lactam ring on the antibiotic. They can be resistant to a very broad range of antibiotics. ESBLs tend to be e. coli or klebsiella and typically cause urinary tract infections but can also cause other infections such as pneumonia. They are usually sensitive to carbapenems such as meropenem or imipenem.
59
Name 3 quinolones
Ciprofloxacin, moxifloxacin, levofloxacin
60
Indications quinolones
reserved as 2nd or 3rd line treatment due to - rapid emergency of resistance - association with c.diff used in: - uti - severe gi - LRTI - ciprofloxaxin is only oral in use witha ction against pseudomonas aerginosa
61
MoA quinolones
inhibit DNA synthesis
62
Spectrum of action quinolones
Good at aerobic gram negative therefore good at uti and gi mox and levo are newer and have enhanced action against gram positive so good for LRTI which can be positive or negative gram
63
adverse effects quinolones
- GI upset - immediate and delayed hypersensitivity Class specific - neuro defecit (lower seizure threshold and hallucinations) - inflammtion and rupture of muscle tendons - prolong QT therefore increase arrythrmias - promote c.diff, specfically hypervirulent 027 strain Caution - patient - ppl w seizures or at risk - ppl growing (risk of arthropathy) - risk factors for prolonged QT eg cardiac disease or elecgtrolyte disturbance or drugs Interactions: - calcium and antacids reduce absorption - ciprofloxacin inhibits some cytochrome p450 increasing toxicity risk of some drugs specifically theophylline - co-pres w NSAIDs increase risk of seizures - co-pres w steroids increase risk of tendon rupture
64
routes of administartion quinilones
oral/IV
65
name two tetracyclines
doxycycline lymecycline
66
indications tetracyclines
acne vulgaris LRTI inc infective exacerbations of COPD (haemophilus influenzae), pneumonia and atypical pneumonia Chlamydia infection adn PID typhoid,anthrax, malaria, lyme disease
67
MoA tetracyclines
inhibit protein synthesis 30S ribosome subunit (bacteriostatic)
68
important adverse effects
- GI upset - hypersensitivity specific to tetracycylines - oesophageal irritaton, ulcerationa dn dysphagia - photosensitivity - discolouration and hypoplasia of tooth enamel in children intracracial hypertension Contrainications - pregnancy and breastfeeding - children less than 12 - renal impaitment
69
routes of administartion tetracyclines
oral
70
sulfonamide antibiotics?
trimethorprim co-trimoaxole (sulfasalazine)
71
indications sulfonamide antibiotics
- trimethoprim 1st line for uncomplicated uti (w nitro and amox) - co-trimoaxole is used for treatment and prevention of pneumocystitis pneumonia in ppl with immunosuppression eg due to HIV infection
72
MoA sulfonamide abx
inhibit folate synthesis
73
spectrum of action sulfonamides
gram positive and negative but lots of resistance
74
adverse effects sulfonamides?
trimethoprim - GI upset - skin rash - hypersensitivity patient - use cautiously in folate deficiency - dose reduction in renal impairment
75
routes of administration sulfonamides
trimethoprim - only oral co-trimoxazole - oral or IV
76
indications vancomycin
- treatment of gram positive infection eg endocarditis, where infection is seveere and/or penicillins cannot be used due to resistance eg MRSA - treatment of abx-associated colitis cuased by c.diff. usually second line after metronidazole
77
MoA vancomycin
inhibit cell wall synthesis
78
spectrum of action vancomycin
gram positive
79
adverse effects vancomycin
most common - thrombophlebitis at infusion site - 'red man syndrome' if infused too quickly (generalised erythema, hypotension, bronchospasm) - nephrotoxic and ototoxic and can cause blood disorders eg neutropenia, thrombocytopaenia (risk increases with co-prescription of aminoglycosides, loop diuretics or ciclosporin)
80
Prevention of adverse effects vancomycin
- infuse slowly - monitor plasma drug conc
81
routes of administartion vancomycin
IV or oral IV for endocarditis oral for c.diff

Finals Pharmacology old (5 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions