Drugs Flashcards
(78 cards)
1
Q
Concentration dependent killing
Vs.
Time dependent killing
A
Kill based on peak concentration (optimal above 10x MIC)
Kill based on amount of time concentration above MIC
2
Q
Inhibitors of cell wall synthesis
A
Penicillins Carbapenems Cephalosporins Aztreonam Vancomycin Bacitracin Cycloserine
3
Q
Inhibitors of protein synthesis/structure
A
Aminoglycosides Chloramphenicol Erythromycin, clindamycin, lincomycin Tetracyclines Streptogramins/linezolid
4
Q
Interference with cell membrane function
A
Polymixin B, colistin
Azole and polyene (antifungals)
5
Q
Interference with DNA/RNA synthesis
A
Rifampin
Fluoroquinones
6
Q
Inhibitors of metabolism
A
Isoniazid, ethambutol
Sulfonamides, trimethoprim
7
Q
Guidelines for selecting and using antimicrobial agents
A
Confirm presence of infection
Determine site of infection
Determine causative organism(s)
Select drug
Follow response and alter therapy as necessary
8
Q
Select a drug based on
A
Sensitivity of the microorganism
Physiochemical properties
Toxicities of the drug
Patient characteristics
9
Q
Reasons to start empiric abx coverage
A
Site of infection difficult to culture
Serious or life threatening infections
Notes: culture site before starting
Gram stains - quick and very informative for selecting
10
Q
Penicillins/cephalosporins
Mechanism of resistance
A
Beta-lactamases
PBP changes
Porin channel changes
11
Q
Aminoglycosides
Mechanism of resistance
A
Enzyme inactivating
12
Q
Macrolides
Mechanism of resistance
A
Methyltransferases that alter drug binding sites on 50s ribosomal subunit
13
Q
Tetracyclines
mechanism of resistance
A
Transport systems that pump drugs out of the cell
14
Q
Sulfonamides
Mechanism of resistance
A
Increased PABA formation
Target enzyme sensitivity
15
Q
Fluoroquinones
Mechanism of resistance
A
Target enzyme changes
Drug efflux
16
Q
Gram positive class
A
Staphylococcus
Streptococcus
Enterococcus
17
Q
Gram negative
Piddly
A
Haemophilus Morexella Morganella Shigella Salmonella (Providencia, neisseria)
18
Q
Gram negative
Fence
A
Proteus
Eschericia coli
Klebsiella
19
Q
Gram negative
SPACE
A
Serratia Pseudomonas Acinetobacter Citrobactor Enterobactrer
20
Q
Atypical class
A
Chlamydia
Mycoplasma
Legionella
21
Q
Anaerobes class
A
Peptostreptococcus
Bacteroides
Clostridium
22
Q
Post Antibiotic Effect (PAE)
A
Persistent effect on bacterial growth following brief exposure of organisms to a drug
Aminoglycosides & fluoroquinones
23
Q
Penicillin G
A
Binds PBP & blocks crosslink peptidoglycan
Strep, some enterococcus
Acid labile
Rheumatic fever prophylaxis
24
Q
Penicillin VK
A
Binds PBP
Strep, some enterococcus
Acid stabile
Absorption not slowed by food
25
Anti penicillinase penicillin (anti staph)
Methicillin, nafcillin, oxacillin (IV drugs)
cloxacillin, dicloxacillin (PO drugs)
Nafcillin - hepatic elimination
Strep and beta lactamase staph
26
Ampicillin
Bind PBP
Strep, ENTEROCOCCUS, and PEK gram neg
Diarrhea is major side effect
27
Amoxicillin
Bind PBP
Strep, enterococcus, PEK gram neg
Absorb not slowed by food
Diarrhea less so than amp
28
Carbenicillin
Bind PBP
Strep, PEK and SPACE gram neg (pseudomonas requires high concentrations)
Absorption not delayed by food
High urine but low systemic concentration
29
Ticarcillin
Bind PBP
Strep, PEK and SPACE gram neg (pseudomonas req. high concentration)
High sodium load!! (CHF, renal fail, hypernat.)
30
Pipercillin
Bind PBP
Strep, enterococcus, PEK and SPACE gram neg
Sodium load but much lower than ticarcillin
31
Adding beta lactamase inhibitor to penicillin
Augmentin- amox/clavulanic acid
Unasyn- amp/sulbactam
Zosyn- pipercillin/ tazobactam
Adds staph and anaerobes
32
Cephalosporins (general)
Bind PBP inhibit peptidoglycan crosslink
Oral admin - rapid, thorough absorption
Most renal excretion
Probenecid interaction: prolonged excretion if tubular secreted
Warfarin: potentiates bleeding
33
Cephalosporins (General)
Binds PBP and inhibits peptidoglycan crosslink
Oral admin - rapid, thorough absorption
Probenicid: prolong excretion of tubular secreted drugs
Warfarin: potentiation of anticoagulant effects
34
1st Gen. Cephalosporins
| Cephalexin, Cefazolin
Coverage: strep, staph, piddly
cefazolin - surgical prophylaxis, long 1/2 life
minor skin and soft tissue infections
35
2nd Gen. Cephalosporins
| Cefaclor, Cefuroxime
Coverage: strep, staph, H. Flu., M. Cat., PEK
Cefaclor - serum-like sickness in kids
36
2nd Gen. Cephalosporins (Cephalomycins)
| Cefotan, Cefoxitin
Coverage: strep, staph, H. Flu., M. Cat., PEK, Anaerobes
Cefotan has NMTT group (alcohol & bleeding)
Used for abdominal/GI surgery, more severe skin and sot tissue infections
37
3rd Gen. Cephalosporins
| Ceftriaxone
Coverage: strep, H Flu, M Cat, PEK, SACE
Good choice for meningitis but need high concentrations
Ceftriaxone hepatic excretion (diarrhea)
38
3rd Gen. Cephalospporins (Anti-pseudomonals)
| Ceftazidime, Cefoperazone
Coverage: strep, poor staph, H Flu, M Cat, PEK, SPACE
Cefoperazone has NMTT group (alcohol & bleeding)
Cefoperazone is hepatc excretion (diarrhea)
Community acquired Pneumonia
39
4th Gen. Cephalosporins
| Cefapime
Coverage: strep, staph, H Flu, M Cat, PEK, SPACE
nosocomial acquired pneumonia
40
5th Gen. Cephalosporins
| Ceftaroline
Coverage: strep, staph (including MRSA), H Flu, M Cat, PEK, SCE
41
Carbapenems (General)
Binds PBP induces cidal effect
Covers most of our general classes
Save for life threatening or multiple organism infections and/or ESBL producing organisms
42
Imipenem
extensive renal metabolism by dehydropeptidase-1 (cilistatin inhibits this enzyme)
seizures - increased risk especially if history; must adjust for renal function
43
Meropenem
Does not cause seizures s can be used for meningitis
44
Ertapenem
No enterococcus or SPACE coverage
Once a day dosing (higher compliance?)
45
Doripenem
Newest carbapenem
46
Aztreonam
Coverage: Gram negs including SPACE
Used when anaphalaxis to penicillin
adverse hematological effects
Save for extreme situations
47
Aminoglycosides
Binds outer membrane of gram - and rearranges LPS and crosses into cell binding 30s and 50s ribosomal subunit decreasing protein synthesis and causing misread RNA
Coverage: Gram- including SPACE
poorly absorbed in GI, excreted in urine almost unchanged
Ototoxicity, Nephrotoxicity, Neuromuscular blockade (rare)
Gent & Tobra want trough under 2
Neomycin - gut decontamination for surgery
Streptomycin - reserved for TB
Hartford Nomogram
48
Vancomycin
inhibits synthesis peptidoglycan polymers by binding D-alanyl-D-alanine precursor
Coverage: gram+ (MRSA & penicillin allergy)
poorly absorbed in GI, renal excretion, usually IV except in C Diff
Red Man Syndrome, ototoxic, nephrotoxic
Can be used for endocarditis prophylaxis
49
Quinupristin/Dalfopristin
Irreversibly binds 50s subunit
Quinupristin - inhibit chain formation (early termination)
Dalfopristin - interferes with peptidyl transferase
individual = static Combo = cidal
MRSA, VRE (faecium), PCN resistant strep pneumo, anaerobes, and some gram-
IV (PICC or central line) because toxic to veins
50
Linezolid
Bind 23s of 50s ribosomal subunit inhibiting protein synthesis
MSRA, PCN resistant strep pneumo, VRE, Vanc intermedia staph aureus
100% bioavailable by IV and PO
thrombocytopenia, superinfection, mitochondrial toxic over long courses
MAO inhibition (SSRIs and cytokine storm)
51
mupirocin
Topical ointment that eliminates MRSA in nares (bactroban)
52
Colistin - Polymixin E
Coverage: Pan-resistant gram negs, such as carbapenem resistant enterobactericae, SPACE and resistant PEK
nephrotoxic and neurotoxic
reserved for last ditch effort
53
Fosfomycin
single dose for MDR UTIs
54
Tigecycline
Coverage: resistant gram- and gram+ and anaerobes, but not pseudomonas or bacteremias
Higher mortality rate, low serum because goes to tissue
Bacteriostatic
55
Daptomycin
Coverage: Gram+ including MRSA and VRE
skin and soft tissue infections, staph aureus bactermia, and endocarditis right side
```
Rhabdomylysis, requires CPK monitoring
Eosinophilic pneumonia (rare)
```
56
Televancin
Skin and soft tissue gram+
Red Man Syndrome, QT prolongation, nephrotoxicity
57
Sulfonamides
Structure similar to PABA, compete for Dihydropteroate synthetase depriving cell of folic acid for DNA synthesis; does not affect host cell
Coverage: Gram+, Gram- piddly and PEK and CE
excreted via glomerular filtration (used for UTI)
Steven Johnson's Syndrome,
Nephrotoxicity - increased with IV make sure pt. is hydrated, crystalluria
Kernicterus - elevated levels of unconjugated bilirubin in fetal blood if given to female in third trimester
Treats acute uncomplicated UTIs, Toxoplasmosis, Pneumocystis carinii, nocardosis, malaria if chloroquine resistant
58
Trimethoprim
Inhibits Dihydrofolate reductase, prevents formation of tetrahydrofolic acid, does affect human enzyme
Coverage: Gram+, Gram- piddly, PEK, and CE; Pneumocystis carinii if used with Dapsone
Renal excretion: most glomerular filtration some secretion
Caution in patients with folate deficiency (pregnant or alcoholic)
Treats acute uncomplicated UTIs or recurrent UTI prophylaxis
59
Bactram
| Sulfamethoxazole/trimethoprim
Synergy combined mechanisms - cidal -reduce resistance
UTIs, respiratory tract infections, GI, STDs, travellers diarrhea
combined adverse effects
Drug of choice for strenotrophomonas maltophilia
Warfarin interaction: one of the worst potentiators
Methotrexate interaction: increase free concentraion
60
Nitrofurantoin
May interfere with early bacterial carb metabolism, inhibiting acetyl CoA
Gram positive resistant (MRSA), some Gram- but not Pseudomonas
Excretion is linear and related to creatinine clearance, impaired GFR = increased toxicity
Pulmonary reactions (sually reversible)
Used almost exclusivley for UTIs, do not use in males because of prostate tissue
61
Methenamine
hydrolyzed to formaldehyde at urine pH, denatures proteins
avoid in hepatic insufficiency (ammonia byproduct) and renal insufficiency (acidosis)
Only used as UTI prophylaxis, increased urine output decreases effects by voiding formaldehyde decreasing exposure time
62
Macrolides (General)
Binds reversibly to 50s ribosomal subunit decreasing protein synthesis - Bacteriostatic
Gram positives and atypicals
Distributes to tissues longer than blood
Very high concentration in alveolar macrophages and leukocytes
Use in Penicillin allergy, Mycoplasma pneumonia, C. trachomatis (no estolate form if pregnant), Legionnaires disease
63
Erythromycin
Estolate form not effected by hepatic metabolism
```
More severe GI symptoms (cramps),
Large IV dose may cause QT prolongation, ototoxicity, and thrombophlebitis
Cholestatic Hepatitis (rare) - DO NOT USE ESTOLATE in PREGNANT WOMEN
```
Motilin stimulation, P-450 enzymes: decreased metabolism of Theophylline, Warfarin, Carbemazepine, cyclosporine
64
Clarithromycin
Picks up H Flu, M Cat, and H Pylori
GI symptoms less severe, Headache, Dizziness, Allergy
P-450 enzymes: decreased metabolism of Theophylline, Warfarin, Carbemazepine, cyclosporine
65
Azithromycin
Picks up H Flu, M Cat, and H Pylori (possibly)
Slow release allows 5 day therapy, but lasts 10 days
GI symptoms less severe, Headache, Dizziness, Allergy
Does not inactivate P-450 enzymes, less worry of drug interactions
66
Clindamycin
Binds 50s ribosomal subunit leading to decrease in protein synthesis
Gram+, anaerobes
90% bioavailability, liver metabolism
Principally associated with diarrhea and C. Diff
67
Chloramphenicol
Binds 50s ribosomal subunit reversibly
Gram+ and -, anaerobes, chlamydia, rickettsia
```
aplastic anemia (idiosyncratic),
grey baby syndrome (babies lack conjugation system so drug builds up)
```
great for meningitis but not first line
68
Quinolones (General)
Inhibit DNA gyrase reducing supercoiling leading to DNA cleavage
Oral dose excellent bioavailability, do not take with Mg, Al, Ca beacuse chelation,
Musculoskeletal tendon rupture, no use
69
Ciprofloxacin
SPACE, atypicals (watch Chlamydia resistance)
most potent against Gram- (pseudomonas)
70
Levofloxacin
SPACE, atypicals, Gram+
71
Moxifloxacin
SACE, atypicals, Gram+, anaerobes, (no UTIs)
Complicated intrabdominal infections
72
Gemifloxicin
Gram+
73
Tetracyclines (General)
Binds 30s reversibly to decrease protein synthesis - static
Gram+ (staph/strep), Gram- (H Flu, Neisseria), atypicals, rickettsia
Photosensitivity
Can replace bone and dentin (don't use in children under 8)
Fanconi-Like Syndrome (if drug outdated) - lethargy, polydipsia, polyuria, proteinuria, acidosis
Di/trivalent cations decrease absorption
Warfarin - enhances anticoag
74
Doxycycline
hepatobiliary secretion
75
Minocycline
hepatobiliary secretion
Dizziness, ataxia, vertigo
76
Tetracycline
renal excretion
77
Oxytetracycline
renal excretion
78
Demeclocycline
renal excretion
used to treat SIADH
