antimicrobial Flashcards
1
Q
narrow spectrum
A
active against Gram-positive or Gram-negative, aerobic or anaerobic bacteria
2
Q
eg of narrow spectrum
A
Vancomycin, colistin, azteronam
3
Q
Broad spectrum
A
active against Gram-positive and Gram-negative, aerobic and anaerobic)
4
Q
eg of broad spectrum
A
Third generation cephalosporin, piperacillin
5
Q
Extended spectrum
A
very wide range activity it may not cover small number of pathogens
6
Q
eg of extended spectrum
A
Carbapenem, tigycycline
7
Q
what drugs act on cell wall synthesis ?
A
cycloserine vancomycin bacitracin penicillin cephalosporin
8
Q
what drugs act on dna gyrase?
A
nalidixic acid
quinolones
9
Q
what drug act on dna dependent rna polymerase ?
A
rifampicin
10
Q
what drugs act on protein synthesis by inhibiting 50s?
A
erythromycin
chloramphenicol
clindamycin
11
Q
what drugs act on protein synthesis by inhibiting 30s?
A
tetracycline spectinomycin streptomycin gentamicin tobramycin amikacin
12
Q
what drug acts on cell membrane ?
A
polymyxins
13
Q
what drugs act on folic acid metabolism?
A
trimethoprim
sulfonamides
14
Q
drugs Inhibit Cell wall synthesis how?
A
acting on formation of peptidoglycan
15
Q
Inhibitors of bacterial cell wall synthesis
A
β-lactam act on the final stages of peptidoglycan synthesis
16
Q
what are the β-lactams
A
penicillin
cephalosporin
carbapenem
monobactam
17
Q
β-lactams characteristics
A
All share β-lactam ring
Principal target is Transpeptidase
All bound to penicillin binding proteins (PBP)
PBP are involved in cell wall construction ( Bactericidal)
18
Q
penicillin structure
A
5-membered thiazolinering fused to β-lactam ring
19
Q
first natural penicillin is produced by ?
A
penicillium
20
Q
resistance to penicillin is a result of what?
A
enzymes = penicillinases
21
Q
negatives of penicillin
A
Breakdown by gastric acidity (poorly absorbed by mouth)
Very rapid excretion by the kidney
Narrow spectrum
22
Q
6-Aminopenicillanic acid (6-APA) is better than benzyl penicillin in terms of what?
A
Antibacterial activity ( broader spectrum)
Stability to bacterial β-lactamases
Pharmacokinetic properties ( better absorption)
23
Q
group 1 penicillin aka
A
parenteral penicillin
24
Q
what are the parenteral penicillins?
A
Benzyl penicillin
Procaine penicillin (long acting)
25
group 2 penicillin aka
Oral penicillin
26
what is a kind of Oral penicillin?
Penicillin V
27
Classifications of penicillin is on the basis of ....
antibacterial spectra
28
group 3 aka
Anti-staphylococcal penicillin
29
whats a kind of Anti-staphylococcal penicillin?
Cloxacillin
30
group 4 aka
Extended-spectrum penicillin
31
what are Extended-spectrum penicillin active against?
Enterobacteriacea except Pseudomonas
32
what are the kinds of Extended-spectrum penicillin?
Ampicillin
| Amoxicillin
33
group 5 aka
penicillin active against Pseudomonas aeruginosa
34
what is an example of penicillin active against Pseudomonas aeruginosa?
Piperacillin
35
group 6 aka
β-lactamase-resistant penicillin
36
β-lactamase-resistant penicillin is active against what?
gram negative only
37
whats an example of β-lactamase-resistant penicillin?
Temocillin
38
what causes Hypersensitivity reaction Anaphylactic reaction ( rare, rapid reaction within minutes, nausea, vomiting , dyspnea and coma, fatal) as side effects?
penicillin
39
what causes Purities and urticarial reaction (develop within 1-3days )
Skin eruptions usually maculopapularrashes (commonest) as side effects?
penicillin
40
what causes Hemolytic anemia and thrombocytopenia
| Neurotoxicity with high doses (rare) as side effects?
penicillin
41
cephalosporin structure
6-membered dihydrothiazinering fused to a β-lactam ring
42
cephalosporins are derivatives of ....
7-aminocephalosporanicacid (7-ACA)
43
Cephalosporin advantages over penicillin
More stable to enzymes ( Staphylococcus penicillinases)
Broader spectrum
Less prone to cause hypersensitivity
Oral and parenteral preparations
44
penicillin is better than cephalosporin in that...
more active against Enterococci
45
cephalosporin 1st gen
Cephalexin
| Cephazolin
46
cephalosporin 2nd gen
Cefuroxime
| Cefoxitin
47
cephalosporin 3rd gen
Cefotaxime
Ceftriaxone
Ceftazidime (antipseudomonal)
48
cephalosporin 4th gen
Cephepime
49
cephalosporin 1st gen active against
Wide range of Gram-positive and negative except (Pseudomonasand Haemophilus)
Streptococcus, Staphylococcus, Enterobacteriacae
50
cephalosporin 2nd gen active against
Wide range of Gram-positive and negative including Haemophilusand anaerobes
51
Cefuroxime: like cephalexin plus ...
active against Haemophilusand S. pneumoniae
52
cephalosporin 3rd gen active against
Wide range but more anti-Gram-negative than second generation
53
Cefotaxime: active against
Enterobactericae, Haemophilusand S. pneumoniae and not active against Pseudomonasspp
54
cephalosporin 4th gen is
Anti-Gram-negative
55
cephepime
active against Enterobacteriacaeand Pseudomonas
56
what causes Local pain and thrombophlebitis at site of injection +
Hypersensitivity reaction in 0.5-10% of patients (10% cross reaction with penicillin allergy) as side effects?
cephalosporin
57
what causes Hepatotoxicity and Gastrointestinal disturbance as side effects?
cephalosporin
58
what causes Thrombocytopenia and Pseudomembranous colitis?
cephalosporin
59
Monobactams aka
Monocyclic β-lactam antibiotics
60
example of monobactam
Aztreonam
61
Aztreonam
Narrow spectrum (anti-Gram-negative aerobic bacilli)
Bactericidal
Stable to bacterial enzymes
62
what drug is isolated from Streptomyces's?
Carbapenem
63
what drug has Potent activity against a broad range of Gram-positive and negative bacteria?
Carbapenem
64
what drug is Resistant to lysisby β-lactamases?
Carbapenem
65
what are 2 important carbapenems?
Imipenem
| Meropenem
66
Imipenem char
Not stable, it need to be combined with cilastatinto be more stable
Safe
Broad spectrum
Seizures and transient changes in liver enzymes are main side effects
67
Meropenem
Stable and broad spectrum
Side effects .. Similar toimipenem
68
Glycopeptides
Vancomycin& Teicoplanin
69
Glycopeptides Mode of action
Act on cell wall synthesis at a stage prior to B-lactams
Not act on PBP & not inactivated by B-lactamases enzymes
70
what drug has these characteristics ?
Activity is restricted to Gram-positive bacteria only
Poorly absorbed from GI
IM injections are painful
Glycopeptides
71
what drug has these characteristics ?
Nephrotoxic Ototoxic
Reversible neutropenia and thrombocytopenia
Glycopeptides
72
_______ is less nephrotoxic than vancomycin
Teicoplanin
73
Glycopeptides Clinical use
MRSA
Patient allergic to penicillin or cephalosporin with Staphylococcus or Streptococcal infections
74
...... indirectly inhibit DNA synthesis
Sulphonamides& Trimethoprim
75
________ directly inhibit DNA-gyrase
Quinolones
76
________ bind to bacterial ribosome and inhibit protein synthesis
Nitrofurantoin
77
________ inhibit DNA dependent RNA polymerase
Rifampicin
78
true or false Sulphonamides& Trimethoprim act on same stages of folic acid synthesis
false
79
Sulphonamide inhibit ....... while man cell require performed vitamin ( basis of selective toxicity)
early stages of folic acid synthesis and bacteria cannot utilize exogenous source of the vitamin
80
Trimethoprime act on...... (selectively it has high affinity for bacterial enzymes)
later stages of folic acid synthesis by inhibiting dihydrofolate reductase
81
sulfonamide char
Broad spectrum of activity
Well absorbed after oral administration
82
some side effects of sulfonamide
Crystalluria and hematuria
Hypersensitivity (fever and rash) or urticarial rashes
Stevens-Johnson syndrome (rare but could be fatal)
83
what does sulfonamide cause in patients with G6PD deficiency?
hemolytic anemia
84
what drug causes Megaloblastic anemia and Liver damage as side effects?
sulfonamide
85
what drug is contraindicated in pregnancy because it interferes with bilirubin transfer in fetus?
sulfonamide
86
trimethoprim is active against what?
Gram-positive aerobic bacteria and Enterobactericaeae
87
what drug is rapidly absorbed from GI?
trimethoprim
88
whats the most commons side effect of trimethoprim?
olic acid deficiency may lead to megaloblasticanemia if used for long time
89
whats mainly used for uti in combo with sulfonamide
trimethoprim ( as cotrimoxazole)
90
Nitrofurantoin moa
Act on bacterial mRNA, ribosomal proteins
91
what is well absorbed orally?
Nitrofurantoin
92
what drug is used for uti?
Nitrofurantoin
93
side effects of Nitrofurantoin
Nausea and vomiting
Peripheral neuropathy
Hemolysis in patients with G6PDdeficiency
94
quinolones structure
dual ring
95
quinilones moa
inhibiting DNA gyrase (topoisomerase) this will inhibit DNA replication
96
4-quinolones
naladixicacid
97
Fluoroquinolones
Ciprofloxacin
98
Ciprofloxacin characteristics
More potent
Broader spectrum (UTI, Osteomyelitis, STD, Pneumonia)
Better absorption and distribution (oral & parenteral)
99
quinolones side effects
GI ( nausea, vomiting & diarrhea)
Pseudomembranous colitisSkin rash
CNS (benign intracranial hypertension) and psychosis
Thrombocytopenia
100
Metronidazole structure
5-nitroimidazole
101
Metronidazole moa
Exert its effect by reduction of the nitro group to amine under low redox potential
102
Metronidazole active against
obligate anaerobes & helicobacter and protozoa (T. vaginalis, Giardia, E. histlolytica)
103
what drug is rapidly and completely absorbed from GI?
Metronidazole
104
Metronidazole side effects
CNS, confusion and seizures
Peripheral neuropathyGI (nausea, vomiting & diarrhea)
Neutropenia (reversible)
Metallic taste
Rash and pruritis
105
what drug causes metallic taste
Metronidazole
106
what drug causes Pseudomembranous colitis?
quinolones
