Antibiotics Flashcards

(43 cards)

1
Q

Name the antibiotics that effect cell wall synthesis? Folate synthesis? Nucleic acid synthesis? Protein synthesis?

A

cell wall synthesis: beta lactams - Penicillins, cephalosporins, carbapenems, monobactam; glycopeptides - vancomycin, teicoplanin; polymyxins - colistin

Folate synthesis: Sulfamethoxazole, trimethoprim

Nucleic acid synthesis: DNA Synthesis - Fluoruquinolones, metronidazole; RNA polymerase - rifamycins

Protein synthesis: 30S subunit - Aminoglycosides, tetracyclines; 50s subunit - macrolides, clindamycin, linezolid, chloramphenicol, Fusidic acid

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2
Q

antibiotics in co-amxiclav?

A

amoxicillin and clavulanic acid

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3
Q

antibiotics in tazocin?

A

piperacillin and tazobactam

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4
Q

Cephalosporin structure?

A

Contain a beta-lactam ring attached to a six-membered nuclear structure
(five in penicillin) - allows synthetic modifi cation at two sites (one in penicillin) - therefore the largest group of available antibiotics

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5
Q

Which is the broadest spectrum beta lactam antibiotic?

A

Carbapenums

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6
Q

Which bacteria is Aztreonam active against? SEs? Class?

A

Monobactam
only active against Gram-negative species including Neisseria meningitidis,
Haemophilus influenzae, Pseudomonas. Given IV/IM. Inhaled preparation
for chronic pulmonary Pseudomonas (cystic fibrosis)

SEs: N&V, GI bleed, rash, raised LFTS, reduced plts, paraesthesia, seizures, bronchospasm.

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7
Q

Which are the non-beta lactam cell wall inhibitors?

A

Includes glycopeptides, eg vancomycin, teicoplanin, and

polymyxins, eg colistin

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8
Q

Nitrofurantoin MOA? uses? SEs?

A

Metabolites interfere with cell growth via ribosomes, DNA,
RNA, and cell wall. Multiple sites of attack means reduced resistance used in uncomplicated UTI
SES: haemolysis, pulmonary fibrosis,
hepatotoxicity

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9
Q

Name 6 penicillins

A

Penicillin G (benzylpenicillin), Penicillin V (Phenoxymethylpenicillin), amoxicillin/ampicillin (amoxicillin PO, ampicillin IV), Co-amoxiclax, Piperacillin+tazobactam, flucloxacillin

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10
Q

Benzylpencillin indiciations? route? SE?

A

Gram +ve: streptococci (chest, throat, endocarditis, cellulitis),
meningococcus, diphtheria, anthrax,
leptospirosis, Lyme disease

IV
SE: allergy,rash, N+V, C.diff, cholestasis

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11
Q

Penicillin V indications?

A

Prophylaxis: splenectomy/hyposplenism,

rheumatic heart disease

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12
Q

Ampicillin/amoxicillin MOA? indications? route? SE?

A

Amino acid side chain extends
penicillin spectrum to include enterobacteria

URTI, sinusitis, chest, otitis media, UTI, H. pylori

SE: as per penicillin G, rash with EBV.

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13
Q

Co-amoxiclav indications?

A

Used if resistance to narrower spectrum
antibiotics: chest,
pyelonephritis, cellulitis, bone

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14
Q

Piperacillin+tazobactam Indications? properties? SE?

A

Broad spectrum including Gram
+ve, Gram -ve, Pseudomonas:
neutropenic sepsis, hospitalacquired/
complicated infection.

Tazobactam has reduced penetration of blood brain barrier

SE: SE: as per penicillin G.
Myelosuppression with prolonged use (rare).

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15
Q

Flucloxacillin indications? SE?

A

beta-lactamase resistant, Staphylococcus:
skin, bone, post-viral
pneumonia.

SE: allergy, rash, N+V, cholestasis

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16
Q

Name the 1st, 2nd and 3rd generation cephalosporins

A

1st: Cefalexin
2nd: Cefuroxime,
3rd: Cefotaxime, ceftriaxone, ceftazidime

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17
Q

Cephalosporins SE? Caution? (4)

A

Reduced first line use in UK due to risk of C.diff

Caution: false +ve
urinary glucose and
Coomb’s test

SE: allergy, rash,
N&V, cholestasis.

Ceftriaxone can
precipitate in urinary
tract and biliary tree =
pseudolithiasis.

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18
Q

Indications of cefalexin?

A

Gram +ve infection: UTI, pneumonia

19
Q

Cefuroxime indications?

A

Gram +ve and Gram -ve (Enterobacteriaceae,

H. influenzae): UTI, sinusitis, skin, wound.

20
Q

cefotaxime indications?

A
Broad spectrum (not Pseudomonas, Enterococcus
spp, Bacteroides).
21
Q

Ceftriaxone indications? SE?

A
Meningococcus. Broad spectrum (not Pseudomonas,
Enterococcus spp, Bacteroides
Ceftriaxone can
precipitate in urinary
tract and biliary tree =
pseudolithiasis.
22
Q

Ceftazidime indications?

A

Broad spectrum including Pseudomonas but
reduced activity against Gram +ve: empirical treatment
of neutropenic sepsis.

23
Q

Name 3 carbapenems? SEs?

A

Imipenum (Imipenem
given with cilastatin to reduce renal
metabolism), meropenum, ertapenum

SE: N&V, C. difficile, rash, eosinophilia,
reduced plts, raised LFTs, seizures.

24
Q

Name two lipopeptides and two polmyxins

A

lipopeptides: vancomycin, teicoplanin
polymyxins: colistin, polymyxin B

25
Lipopeptides indications? SEs? Monitoring?
Complicated Gram +ve including MRSA. Oral for C.difficile (not absorbed). SEs: nephrotoxic (monitor creatinine, care with other nephrotoxics) ototoxic, reduced plts. monitor creatinine
26
polymyxins indication? consideration?
nephrotoxicity occurs in 50% Inhaled colistin for ventilator-associated pneumonia
27
Name the antibiotics that inhibit protein synthesis?
Protein synthesis: 30S subunit - Aminoglycosides, tetracyclines; 50s subunit - macrolides, clindamycin, linezolid, chloramphenicol, Fusidic acid
28
Name 3 aminoglycosides. Indications? SEs? Monitoring?
Gentamicin, tobramycin, amikacin Gram Ωve infection (reduced activity against most Gram +ve and anaerobes). Tobramycin has increased activity against Pseudomonas. Amikacin has least resistance. SEs: nephrotoxic (monitor drug levels and serum creatinine), vestibular toxicity, ototoxicity.
29
Name 3 macrolides, indications, SEs?
Azithromycin, Clarithromyin, erythromycin Gram +ve cocci (not enterococci and staphylococci), syphilis, chlamydia. ``` SEs (increased with erythromycin): GI, cholestasis, prolonged QT. Cytochrome P450 inhibition (reduced with azithromycin): increased warfarin, rhabdomyolysis with statins, increased calcineurin inhibitor levels. ```
30
Name three tetracyclines? Indications? CI? SE?
tetracycline, doxycycline and tigecycline Exacerbation COPD, chlamydia, Lyme disease, mycoplasma, rickettsiae, brucella, anthrax, syphilis, MRSA, malaria prophylaxis. CI: pregnancy, <8yr (permanently stain teeth) SEs:N&V, C. difficile, fatty liver, idiopathic intracranial hypertension. tigecycline is used for Gram +ve and Gram -ve including beta-lactam-resistant strains. SEs: N&V, photosensitivity, raised LFTs.
31
Clindamycin indications? SEs?
Gram +ve cocci (not enterococci), | MRSA, anaerobes
32
Linezolid indications?
Gram +ve cocci, MRSA, VRE, anaerobes, mycobacteria Its a weak monoamine oxidase inhibitor (check interactions) - myelosuppression, optic neuropathy.
33
Chloramphenicol indications? considerations?
Gram +ve, Gram Ωve, anaerobes, mycoplasma, chlamydia, conjunctivitis (topical). Systemic use limited by myelosuppression
34
Fusidic acid indication? SEs?
Staphylococci. SES: GI, raised LFTs.
35
Coagulase negative vs positive staphylococci examples? virulence?
Coagulase-negative staphylococci - Staph epidermidis positive - staph aureus coagulase negative is less virulent - pathogenicity only likely if underlying immune system dysfunction or foreign material (prosthetic valve/joint, IV line, PD catheter, pacemaker)
36
Different presentations of coagulase positive staphylococcus?
1. Toxin release causes disease distant from infection. Includes: Scalded skin syndrome (bullae and desquamation due to epidermolytic toxins (no mucosal disease, less skin loss compared to toxic epidermal necrolysis) preformed toxin in food - sudden D+V toxic shock: fever, confusion, rash, diarrhoea, low BP, AKI, multiorgan dysfunction. Tampon associated or occurs with (minor) local infection. 2. Local tissue destruction: impetigo, cellulitis, mastitis, septic arthritis, osteomyelitis, abscess, pneumonia, UTI. 3. Haematogenous spread: bacteraemia, endocarditis, ‘metastatic’ seeding.
37
Symptoms of toxic shock? Causative organism
fever, confusion, rash, diarrhoea, low BP, AKI, multiorgan dysfunction. coagulase positive staph
38
How is staph aureus resistance defined?
by stability to | meticillin, ie meticillin-resistant Staph. aureus (MRSA)
39
How is vancomycin resistance classified in staph aureus?
classified according to the amount of vancomycin needed to inhibit bacterial growth: vancomycin-intermediate Staph. aureus (VISA) and vancomycin- resistant Staph. aureus (VRSA).
40
Risk factors for MRSA colonisation?
antibiotic exposure, hospital stay, surgery, nursing home residence.
41
MRSA infection treatment?
vancomycin (for MRSA), teicoplanin
42
oral agents with activity against MRSE?
clindamycin, co-trimoxazole, doxycycline, linezolid
43
What are the major classes of gram positive cocci?
staphylococci streptococci enterococci