Antimicrobials, Antifungals and Antiprotozoal Flashcards
1
Q
Inhibition of peptidoglycan crosslinking by blocking transpeptidase
A
Penicillin, cephalosporins, methicillin, ampicillin, piperacillin, aztreonam, imipenem
2
Q
Inhibit peptidoglycan synthesis
A
Bacitracin, Vancomycin
3
Q
Damage DNA
A
Metronidazole
4
Q
Block 30s
A
Aminoglycosides, Tetracyclines
5
Q
Block 50s
A
Macrolides, Chloramphenicol, Clindamycin, Streptogramins (Quinupristin, dalfopristin), linezolid
6
Q
Penicillins
A
structural analogs of D-ala, D-ala
7
Q
Methicillin toxicity
A
Interstitial nephritis
8
Q
Ampicillin/Amoxicillin HELPSS kill enterococci
A
H. influenzae, E. coli, Listeria, Proteus, Salmonella, Shigella, enterococci
9
Q
Beta-lactamase producers
A
Staph. aureus, H. influenzae, Bacteroides, other Gram -ve bacteria
10
Q
1st generation cephalosporins
A
Cefazoline, Cephalexin: gram +ve cocci- Proteus, E. coli, Klebsiella pneumoniae
11
Q
1st generation cephalosporins
A
prophylactically used within 2 hr of the first incision during surgery
12
Q
2nd generation cephalosporin
A
Cefoxitin, Cefaclor, Cefuroxime: Gram +ve cocci- H. influenzae, Enterobacter aerogenes, Neisseria, Proteus, E. coli, Klebsiella, Serratia
13
Q
3rd generation cephalosporin
A
Ceftriaxone, Cefotaxime, Ceftazidime: Better activity against Gram -ve bacteria due to Beta-lactamase resistant properties
14
Q
3rd generation cephalosporin
A
Ceftriaxone: meningitis and gonorrhea; Ceftazidime: Pseudomonas
15
Q
4th generation cephalosporin
A
Cefepime: Pseudomonas and Gram +ve organisms
16
Q
Cefamandole
A
Disulfiram-like reaction
17
Q
Cephalosporine toxicity
A
Increased nephrotoxicity of Aminoglycosides
18
Q
Aztreonam
A
inhibits cell wall synthesis by binding to PBP3, Beta-lactamase resistant; synergistic with aminoglycosides
19
Q
Activity against Gram -ve rods only
A
Aztreonam
20
Q
For penicillin allergic patients and those with renal insufficiency who cannot tolerate aminoglycosides
A
Aztreonam
21
Q
Imipenem
A
Inhibits cell wall synthesis by binding to PBP; Beta-lactamase resistant
22
Q
Imipenem
A
Broad spectrum- Gram +ve cocci, Gram -ve rods, anaerobes
23
Q
Always administered with Cilastatin
A
Imipenem (Cilastatin is inhibitor of renal dihydropeptidase-I, an enzyme which inactivates imipenem in renal tubules)
24
Q
Imipenem toxicity
A
Seizures
25
Meropenem
Reduced risk of seizures and stable to dihydropeptidase-I
26
Binds to D-ala D-ala and inhibits cell wall mucopeptide formation
Vancomycin
27
Vancomycin
Used for multidrug resistance
28
Vancomycin toxicity (NOT)
Nephrotoxicity, Ototoxicity, Thromnbophlebitis, Flushing
29
Red man syndrome
Vancomycin due to histamine release; pretreat with antihistamines
30
Vancomycin resistance
Plasmid/Transposon acquired: Van A ligase substitutes D-lactate for D-alanine that prevents binding of vancomycin to its binding site
31
Prevents muco-peptide transfer into growing cell wall
Bacitracin
32
Depolarization of cellular membrane by disrupting bacterial membrane through creation of transmembrane channels
Daptomycin
33
Daptomycin (lipopeptide)
treatment for invasive MRSA
34
Inactivated by surfactant thus ineffective for pneumonia
Daptomycin
35
Daptomycin- Adverse reactions
Myopathy, CPK elevation
36
Linezolid
Inhibits protein synthesis: Binds to 50s and prevents formation of functional initiation complex
37
Linezolid- Adverse reactions
Thrombocytopenia, Optic neuritis, Serotonin syndrome
38
Antibiotic with high risk for serotonin syndrome
Linezolid
39
Require O2 for uptake therefore ineffective against anaerobes
AminOglycosides
40
Aminoglycosides: MOA
Inhibit formation of initiation complex, cause misreading of mRNA
41
Resistance to aminoglycosides
Acetylation, phosphorylation or adenylation- plasmid/transposon acquired; In pseudomonas- decreased entry into bacteria
42
Aminoglycosides
Gram -ve rods
43
Aminoglycosides toxicity
Nephrotoxicity (increase with cephalosporin), Ototoxicity (when used with loop diuretcis), Teratogens
44
Gentamicin in large doses or intrapleurally
Neuromuscular paralysis
45
Tetracyclines: MOA
bind to 30s and inhibit binding of aminoacyl-tRNA to A-site
46
Tetracycline clinical use
Borrelia, Mycoplasma, Rickettsia, Chlamydia
47
Tetracyclines toxicity
Discoloration of teeth, inhibition of bone growth in childern, photosensitivity
48
Tetracyclines resistance
Efflux pump
49
Doxycycline
fecal elimination, can be given in patients with renal failure
50
Doxycycline side effects
photosensitivity, pill-induced esophagitis
51
Pill-induced esophagitis
Doxycycline
52
Divalent cations inhibit their absorption in gut (e.g. milk, antacids or iron-containing preps)
Tetracyclines
53
A tetracycline used as a diuretic in SIADH
Demeclocycline- ADH antagonist
54
Macrolides
inhibit translocation by binding to 23s rRNA of the 50s ribisomal subunit
55
Macrolides
Atypical pneumonia
56
Erythromycin
Prolong QT, acute cholestatic hepatitis, eosinophilia, skin rashes
57
Macrolides
Inhibit p450 - increase serum concentrations of theophyllines and oral anticoagulants
58
Macrolide resistance
Efflux pump, methylation of 23s rRNA binding site
59
Macrolide noncompliance
MCC GI discomfort
60
Inhibits peptidyltransferase thus blocking peptide bond formation
Chloramphenicol
61
Chloramphenicol side effects
Anemia (dose-dependent), Aplastic anaemia (dose-independent), Gray Baby Syndrome (premature infants lack UDP-glucuronyltransferase)
62
Chloramphenicol resistance
plasmid-encoded acetyltransferase inactivates drug
63
Clindamycin
inhibit translocation (50s)
64
Anaerobic infections
Above the diaphragm- clindamycin; below- metronidazole
65
Clindamycin
Rx for aspiration pneumonia or lung abscesses
66
Clindamycin side effect
Pseudomembranous colitis
67
Inhibit dihydropteroate synthase (PABA antimetabolites)
Sulfonamides (Sulfamethoxazole, Sulfisoxazole, Sulfadiazine)
68
Inhibit dihydrofolate reductase
Trimethoprim
69
Sulfonamides side effects
Hypersensitivity, hemolysis in G6-PD deficiency, nephrotoxicity (tubulointerstitial nephritis), photosensitivity, kernicterus in infants, displace other drugs from albumin (e.g. warfarin)
70
Trimothoprim side effects
Megaloblastic anemia, leukopenia, granulocytopenia, hyperkalemia, toxic epidermal necrolysis, Stevens-Johnson syndrome
71
In high doses (e.g. to treat pneumocystis in AIDS), can act as a K-sparing diuretic--Hyperkalemia
Trimethoprim
72
Inhibit DNA-gyrase (topoisomerase-II) and induce fractures in bacterial chromosome
Fluoroquinolones
73
Must not be taken with antacids
Fluoroquinolones and Tetracyclines
74
Fluoroquinolones side effects
Adults: damage to cartilage, tendonitis and tendon rupture; Kids: leg cramps and myalgia
75
Binds to DNA--> unravels DNA helical structure--> breaks DNA strands (DNA damage)
Metronidazole
76
Pyridoxine (Vit B6 analogue)
INH
77
Bacterial catalase-peroxidase (KatG) needed to form active drug
INH
78
INH side effects
Neurotoxicity, Seizures, Hepatotoxicity, drug-induced lupus
79
INH resistance
Decreased activity of bacterial catalase peroxidase; modification of protein target binding site for INH
80
Drugs metabolized by Acetylation
INH, Dapsone, Hydralazine, Proacainamide
81
anti- TB drug that prevents transcription of DNA into mRNA
Rifampin
82
Rifampin: MOA
Inhibits DNA-dependent RNA-polymerase (Primase)
83
Drug used for meningococcal prophylaxis and for chemoprophylaxis in contacts of children with H. influenzae type B
Rifampin
84
Rifampin: side effects
Amplifies P-450 (RifAMPin), Red/Orange body fluids
85
Rifampin + Vancomycin
MRSA endocarditis
86
Staph. endocarditis
Nafcillin + Gentamycin
87
anti-TB drug that inhibits mycolic acid production by blocking mycobacterial pyrazinamidase
Pyrazinamide
88
anti-TB drug that works best at low pH (acidic) hence effective against intracellular (mycobacteria in phagolysosomes within macrophages) organisms.
Pyrazinamide
89
Drug that delays resistance to Dapsone in leprosy patients
Rifampin
90
Pyrazinamide side effects
Hyperuricemia, Hepatotoxicity
91
anti-TB drug that decreases carbohydrate polymerization of mycobacterial cell wall by blocking arabinosyltransferase
Ethambutol
92
Ethambutol toxicity
Red-green color blindness, decreased visual acuity, central scotoma
93
Resistance mechanism by increasing activity of enzymes involved in cell wall polysaccharide synthesis
Ethambutol resistance
94
Empiric therapy for community-acquired pneumonia
Outpatient: Macrolide; Inpatient: Fluoroquinolone; ICU: Beta-lactam + fluoroquinolone or azithromycin
95
Binds ergosterole--> pokes holes
Amphotericin B
96
Amphotericin B
serious systemic mycosis; intrathecally for fungal meningitis; supplement with potassium and magnesium
97
Amphotericin B toxicity
fever and chills, hypotension, nephrotoxicity, arrythmia, anemia, IV phlebitis; hydration reduces nephrotoxicity
98
Amphotericin B
Hypokalemia--> weakness and arrhythmia; T-wave flattening, ST-depression, prominent U-wave, premature atrial and ventricular contractions; ventricular tachycardia or fibrillation
99
Amphotericin B
severe toxicity (anemia) in HIV +ve patient taking AZT (Zidovudine)
100
Premedicate with antipyretic and antihistaminics for this antifungal drug
Amphotericin B
101
antifungal drug causing toxicity due to binding to human cell membrane cholesterol
Amphotericin B
102
antifungals that inhibit ergosterol synthesis by inhibiting p-450 and thus blocking conversion of lanosterol to ergosterol
Azoles
103
Cryptococcal meningitis in AIDS: DOC
Fluconazole
104
drug that blocks synthesis of hormones and causes gynecomastia
Ketoconazole
105
antifungal drug used in hypercortisolism
Ketoconazole
106
Azole side effect
Liver dysfunction, gynecomastia and p-450 inhibition
107
Avoid these drugs with azoles
warfarin, oral hypoglycemics, cyclosporine, tacrolimus, phenytoin, INH, Rifampin
108
antifungal that inhibits both fungal DNA and RNA
Flucytosine
109
Flucytosine toxicity
Bone marrow suppression
110
antifungal that inhibits cell wall synthesis by inhibiting 1,3-Beta-D-glucan (major polysaccharide component of fungal cell wall
Caspofungin
111
DOC for invasive aspergillosis
Caspofungin (CAsper)
112
Caspofungin toxicity
Flushing
113
antifungal that inhibits the fungal enzyme Squaline epoxide and thus decreases ergosterol synthesis
Terbinafine
114
drug to treat dermatophytosis especially onychomycosis
Terbinafine
115
Terbinafine side effects
Abnormal LFTs, visual disturbances
116
antifungal that interferes with microtubule function and disrupts mitosis
Griseofulvin
117
antifungal that revs up cytpchrome P450 and increases warfarin metabolism that further decreases effectiveness of warfarin and requires to increase the dosage of warfarin
Griseofulvin
118
Griseofulvin side effects
Teratogenic, Headache
119
Rx for Toxoplasmosis or P. falciparum
Pyrimethamine
120
Rx for T. brucei
Suramin and Melarsoprol
121
Rx for T. cruzi
Nifurtimox
122
Rx for Cryptosporidiosis
Nitazoxanide
123
Rx for leishmaniasis
Sodium stibogluconate
