Antibiotics I Flashcards

1
Q

what antibiotic classes target the cell wall and the cell membrane?

A

beta lactams, glycopeptides (vancomycin, telavancin), cyclic lipopeptide (daptomycin)

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2
Q

what are the categories of beta lactams?

A

penicillins, cephalosporins, carbapenems and monobactams

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3
Q

what is the function of beta lactam antibiotics?

A

inhibit bacterial wall synthesis

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4
Q

what is the MOA of penicillins?

A

interferes with transpeptidation of peptidoglycans in cell wall, structural analogs of PBP binding site (PBPs are enzymes that facilitate cross-linking and provide stability)

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5
Q

what are the subgroups of penicillins?

A

natural: penicillin G and VK
aminopenicillins: ampicillin, amoxicillin
penicillinase-resistant penicillin: nafcillin, oxacillin, dicloxacillin
anti-pseudomonal: carbenicillin
penicillin/beta lactam inhibitors: zosyn, augmentin, unasyn

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6
Q

what penicillins are used for narrow spectrum?

A

penicillin VK, penicillin G, nafcillin, oxacillin and dicloxacillin

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7
Q

what penicillins are used for broad spectrum?

A

amoxicillin, ampicillin, augmentin, zosyn, unasyn

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8
Q

what is the spectrum of activity for penicillin VK and G?

A

greatest activity against non-beta lactamase producing gram positive organisms, gram negative cocci (Neisseria meningitides)

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9
Q

what route is penicillin VK?

A

PO

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10
Q

what route is penicillin G?

A

IV/IM

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11
Q

what are the types of penicillin G?

A

Procaine Penicillin G: rapid acting, measured in units
Benzathine Penicillin G: Long acting, measured in units
Combined Repository (CR):combination of procaine and benzathine; must dose based upon benzathine component

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12
Q

what is the prophylaxis for rheumatic fever?

A

Benzathine Penicillin G 1.2 million units once a month

Continue x 5 years to age 21,whichever is longer – lifelong if valvular disease present

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13
Q

how long is the treatment duration of rheumatic fever with carditis and residual heart disease?

A

10 years or until 40 years old, whichever is longer, lifetime prophylaxis may be needed

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14
Q

how long is the treatment duration of rheumatic fever with carditis and without residual heart disease?

A

10 years or until 21 years old, whichever is longer

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15
Q

how long is the treatment duration of rheumatic fever without carditis?

A

5 years or until 21 years old, whichever is longer

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16
Q

what is treponema pallidum?

A

syphilis

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17
Q

if a patient has primary or secondary syphilis and has no penicillin resistance, what do we give them?

A

Benzathine PCN 2.4 million units for 1 week

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18
Q

if a patient has tertiary syphilis, what do we give them?

A

Benzathine PCN 2.4 million units for 3 weeks

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19
Q

what do we give syphilis patients experiencing neurological symptoms?

A

Aqueous Crystalline Penicillin G (IV Penicillin G) for 10-14 days

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20
Q

is Neisseria meningitides gram positive or negative?

A

negative

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21
Q

how do you treat neisseria meningitides?

A

high dose penicillin G, empirical treatment of ceftriazone

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22
Q

what prophylaxis is used for neisseria meningitides?

A

rifampin, if pregnant use ceftriaxone

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23
Q

what vaccines protect from neisseria meningitides?

A

menactra and bexero

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24
Q

what is the route of oxacillin and nafcillin?

25
what is the route of dicloxacillin?
PO
26
what is the spectrum of activity of oxacillin, nafcillin and dicloxacillin?
penicillinase producing staphylococci and streptococci (not MRSA)
27
what are the indications for oxacillin and nafcillin?
serious staphylococci infections such as endocarditis
28
what are the indications for dicloxacillin?
mild to moderate localized staphylococci infections, especially infections of skin or soft tissue
29
what is MRSA?
methicillin resistant staphylococcus aureus, caused by a mutation with penicillin binding protein
30
what can be used to treat MRSA?
vancomycin, daptomycin, clindamycin, bactrim, doxycycline
31
what is included in our normal flora?
ESKAPE: E. coli, Staph, K. pneumoniae, C. baumannii, P. aeruginosa, E. faecalis and faecium
32
what are the main causative agents for impetigo?
1. staph aureus 2. strep pyogenes
33
how is impetigo treated?
based on number of lesions limited: mupirocin, retapamulin widespread/immunocompromised: dicloxacillin, cephalexin
34
what is the spectrum of activity of ampicillin and amoxicillin?
effective against both gram positive and gram negative organisms, but are not penicillinase resistant amoxicillin is also used in H. pylori combination treatment
35
what are the indications of amoxicillin?
acute otitis media, lower respiratory tract infections, preferred treatment when treating pneumococci
36
what are the indications of ampicillin?
Group B Streptococcus sepsis in neonates (used in conjunction with Gentamicin), listeria, monocytogenes
37
what is the spectrum of activity of augmentin?
can also cover gram negative (E. coli, H. flu, proteus mirabilis), not used for pseudomonas
38
what are the indications of augmentin?
acute bacterial sinusitis
39
what are the indications of unasyn (ampicillin/sulbactam)?
prophylaxis for post op infections in appendicitis
40
what type of bacteria is streptococcus pneumoniae?
gram positive diplococci
41
what is the spectrum of activity of zosyn (piperacillin/tazobactam)?
gram postive and gram negative pseudomonas, E. coli and klebsiella
42
what are the indications for zosyn?
Nosocomial Infections: PNA, intra-abdominal infections (appendicitis,peritonitis), uncomplicated and complicated skin infections (E.Coli and B. frag)
43
what are the 4 basic mechanisms of penicillin resistance?
Beta lactamase (most common): Hundreds of different beta lactamases, some more specific, some general (Pseudomonas) Alteration of PBPs: Methicillin resistance – altered PBPs Impaired penetration – only in Gram negative species due to the impermeable outer membrane of their cell wall, Beta-lactams can enter Gram negatives via porins (protein channels); if they are absent or decreased production, then can alterentrance Active pumping – Efflux pump in gram negatives
44
when should oral penicillins be given?
1 hours before or 2 hours after eating except for amoxicillin (can be taken without meals)
45
what penicillin is primarily excreted by hepatic system?
nafcillin
46
what penicillins are excreted by both hepatic and renal system?
oxacillin, cloxacillin and dicloxacillin
47
what are adverse reactions of penicillin?
usually very safe, non-specific maculopapular rash, GI upset, high doses can cause seizures and renal failure, type I hypersensitivity reactions
48
what are adverse reactions of nafcillin?
neutropenia and interstitial nephritis
49
what is the adverse reaction of oxacillin and nafcillin?
hepatitis
50
what is the adverse reaction of clavulanate?
GI symptoms in elderly, hepatitis and cholestasis
51
what are the potential adverse effects of parental penicillins?
hemolytic anemia, leukopenia, thrombocytopenia, neutropenia, neuropathy, nephropathy in high doses, toxic epidermal necrolysis
52
what are the groups of streptococcus species?
Group A: strep pyogenes Group B: strep agalactiae strep pneumoniae viridans streptococci
53
what can group A streptococcus cause?
erysipelas, cellulitis, necrotizing Fasciitis (streptococcal gangrene), puerperal fever. bacteremia or sepsis, streptococcal pharyngitis (Group A Strep), impetigo, streptococcal toxic shock syndrome, scarlet fever, acute glomerulonephritis, rheumatic fever
54
what is the treatment of choice for most streptococcal infections?
penicillin G and penicillin VK
55
how is erysipelas treated?
no symptoms: oral penicillin or amoxicillin symptoms: parenteral aqueous crystalline penicillin G or ceftriaxone
56
how is necrotizing fascitis treated?
penicillin IV and clindamycin
57
describe Group B streptococcus sepsis in neonates
GBS is found in GI tract and genital tract, maternal colonization in pregnant women is the primary risk factor for GBS infection in neonates and young infants, if GBS is confirmed during screening, penicillin G IV or ampicillin is given intrapartum, in infants diagnosed with GBS, penicillin G is given
58
what are the main drugs in each generation of cephalosporins?
first: cefalexin, cefazolin second: cefoxitin, cefuroxime, cefotetan third: ceftriaxone, ceftazidime fourth: cefipime fifth: ceftaroline