antibiotics Flashcards
Name the naturally occurring PCNs and their ROI.
Penicillin VK (PO) Penicillin G (IV or IM)
Name the Anti-staphylococcal PNCNs.
Dicloxacillin (PO)
Nafcillin (IV)
Oxacillin (IV)
Name the Aminopenicillins
Amoxicillin (PO)
Ampicillin (IV)
Name the Antipseudomonal penicillins
Piperacilline (IV)
Ticarcillin
Name the two Beta-lactamase/PNCN combo
Zosyn (antipseudomonal)
Unasyn (anti-Acinetobacter)
what are first line abx in tx MSSA?
Dicloxacillin (PO)
Nafcillin (IV)
Oxacillin (IV)
(Anti-staphylococcal PNCNs)
what would we use to tx Syphilis ?
Pen G
*only PCN doesn’t require renal dosing??
Dicloxacillin
Nafcillin
Oxacillin
describe the coverage of Anti-Staphylococcal
PCNs (diclox, naf, oxa)
GREAT MSSA COVERAGE
Broader gram + coverage
gold standard for tx of listeria
ampicillin
what would you prescribe Amoxicillin for?
Otitis media
UTIs/URIs
Meningitis (ampicillin)
describe coverage for ampicillin/amox
PCN + added Gram negative coverage (E. coli, H. flu, salmonella)
Enterococcus
Listeria and Shigella (Ampicillin preferred)
β-lactam + β-lactamase Inhibitors include zosyn and unasyn among others, which of the 2 is equivalent to augmentin PO?
unasyn
β-lactam + β-lactamase Inhibitors include zosyn and unasyn among others, which of the 2 is used to tx P. aeruginosa?
zosyn
β-lactam + β-lactamase Inhibitors include zosyn and unasyn among others, which of the 2 is used to tx Acinetobacter?
unasyn
what would you use to tx Human bites + Animal Bites
augmentin
Name the 1st gen cephs?
Cefazolin (Ancef) (IV)
Cephalexin (Kelfex) (PO)
Cefadroxil (Duracef) (PO
Name the 2nd gen cephs (2A)
Cefuroxime (Ceftin)
Cefaclor
Cefprozil
Name the 2nd gen cephs (2B)
Cefoxitin
Cefotetan
Name the 3rd gen cephs
Anti-pneumococcal Cefotaxime Ceftriaxone Cefixime Cefpodoxime
Antipseudomonal
Ceftaz
name 4th gen cephs
Cefepime IV
name 5th gen cephs
Ceftaroline IV
name the abcx prescribes SECOND line for MSSA infection?
1st gen cephs
Cefazolin (Ancef) (IV)
Cephalexin (Kelfex) (PO)
Cefadroxil (Duracef) (PO
what would we use 1st gen cphs to tx?
Skin infections SECOND line for MSSA SSTI UTI Pre-op abx
Out of the cephalosporins what would tx?
Respiratory tract infections
Sinusitis, otitis, etc
2nd gen (2A)
Cefuroxime (Ceftin)
Cefaclor
Cefprozil
Out of the cephs what covers:
Skin infections
MRSA / VRSA
VSE
CeftarolineIV (5th gen)
gram +/- aerobes
out of the cephalosprins which cover pseudomonas?
3rd gen antipseudo -> ceftaz
4th gen -> Cefepime (IV)
name the Anti-pneumococcal cephs
Cefotaxime
Ceftriaxone
Cefixime
Cefpodoxime
what would we prescribe for tx of Gonorrhea ?
Gonorrhea (ceftriax)
what would we prescirbe if their was an infection due to b. fragillis
2B
Cefoxitin
Cefotetan
what ceph covers: gram -
Abdominal infections
GYN infections
includes b.fragilis !!
Cefoxitin
Cefotetan
what could we use ceftaz to tx
HA pneumonia
what would we use to tx Neutropenic fever
Cefepime (Maxipime)
name the carbapenems
Primaxin (imipenem/cilastatin)
Meropenem
Doripenem
Ertapenem
Drug of choice for ceftriaxone-resistant E. coli
carbapenems:
Primaxin (imipenem/cilastatin)
Meropenem
Doripenem
Ertapenem
Name ADRs of carbapenems
Highest risk of seizures
Carbapenem resistant Enterobacteriaceae (CRE)
Expensive
coverage of carbapenems
gram +/- aerobes
name things carbapenems tx:
Ceftriaxone resistant E. coli Klebsiella ESBL Complicated UTI Intraabdominal infection
name coverage of vanco
Gram (+) aerobes & anaerobes
what are indications for using vanco IV
Hospital acquired pneumonia Skin infections (MRSA)
why would you usevanco PO?
tx C. diff - PO
name ADRs of vano
Red-man syndrome
Ototoxicity/ nephrotox
C/I in corn hypersensitivity
Dosing renal & weight adjusted
what is VERY important in putting in your order when dosing vanco
TDM of trough – order 30 min before 4th dose
Name the tetracyclines
Doxycycline (IV or PO)
Tetracycline
Minocycline
indications for tetracyclines:
Respiratory tract infections
Skin infections (MRSA)
Tick-bourne infections
coverage of tetracyclines
Strep
Staph (MSSE, MRSA)
Neisseria sp. (gram (-))
Atypicals (ex. lyme. Mycoplasma, chlamydia)
ADRs of tetracyclines
CI in children under 8 avoid in pregnancy Drug intx w/ Ca, Fe, Mg Al Metabolized in liver GI sensitivity Photosensitivity
what class of dugs has Black box warning for causing tendinopathies (elderly and young)
FQs
what classes of drugs decrease seizure threshold and should be avoided in pts who experience seizures?
FQs
Carbapenems
FQs can tx UTIs EXCEPT:
Moxifloxacin (no gram-)
FQs can tx resp. tract infections EXCEPT
Ciprofloxacin (no gram +)
indications for prescribing FQs
UTI (except moxi)
Respiratory tract infections (except cipro)
Intrabdominal infections
Osteomyelitis
drug class w/ ADRS including: Hypoglycemia/hyperglycemia Delirium in the elderly (mental status change) QTc prolongation
FQs
coverage of FQs
Gram (+) (except cipro)
Gram (-) (except moxi)
Atypical – chlamydia, legionella, mycoplasma
Enterobacteriaceae – H.flu M. cat, Niserria
which class of abx is known to have EXCELLENT atypical coverage?
FQs
what FQs could we use to tx M. tuberculosis
moxi
levo
whoch abx has an ADR of possible causing C. Difficile/ diarrhea
clinda
what abx could we use to tx NF
clinda
coverage of clinda
Strep
Staph (MSSA, MRSA)
Gram (+) anaerobes – w/ PSN allergy
name some indications for prescribing clinda
Skin infections (CA-MRSA) Dental infections Respiratory tract infections Nec fash Pregnant women colonized w/ MRSA
name macrolide abx
Azithromycin (IV or PO)(Z-pak)
Erythromycin (IV or PO)
tx of AOM, pharyngitis in PCN allergy
macrolide (azith/eryth)
coverage of macrolides
Group A strep
GNR – H. flu, M/ cat, Neisseria
Atypicals – chlamydia, legionella, m. pneumonia
what class of abx are NEVER USED for: SEPSIS, urine or soft tissue infections
macrolide
ADRs of macrolides
QTc prolongation (risk of sudden cardiac death) Liver metabolized
macrolides are used to tx respiratory tract infections, pharyngitis in PCN allergy and what else? (2 things)
Chlamydia
Travelers diarrhea
what abx is indicated for coverage of
Anaerobes (b. fragilis + c. diff)
Parasites
Metronidazole (flagyl)
FIRST line for tx of c. diff
Metronidazole (flagyl)
indications to prescribes Metronidazole (flagyl)
Intra-abdominal infections
C. diff – FIRST line
Vaginosis
____________ is often added to other abx when treating intraabdominal infections
Metronidazole (flagyl)
ADRs of Metronidazole (flagyl)
Should not take with alcohol (disulfiram-like reaction)
GI intolerance
Metallic taste
periph. neuropathy
Bactrim is dosed based on the _______ component
trimethoprim
name the abx used to tx opportunistic infections?
name some opportunistic infections
bactrim
pneumocystitis, nocardia, toxoplasmosis
coverage of bactrim
Staph MSSA and MRSA
Mild strep (s. pneumoniae, s. pyogenes)
Gram negatives (ex. E. coli, K. pneumoniae,
Enterobacter (M. catarrhalis, H. flu, Salmonella, shigella)
indications for bactrim
UTIs
Skin and soft tissue infections
Opportunistic infections (pneumocystitis, nocardia, toxoplasmosis) Plasmodium
does bactrim cover atypicals or pseudomonas?
NO!
Strep
Staph (MSSA, MRSA)
Gram (-) aerobes
name some ADRs of bactrim
Hyperkalemia Drug interaction w/ warfarin & phenytoin (INR) Renal dosing Avoid in pregnancy Photosensitivity Bone marrow suppression
______ has a drug interaction w/ warfarin & phenytoin so we should ALWAYS order an INR!!!
bactrim
abx to avoid in pregnancy
bactrim
tetracyclines
FQs
why should we avoid bactrim in pregnancy?
causes bone marrow suppression
name abx where we must monitor trough levels
vanco
Aminoglycosides (gentamycin)
ADRS of Aminoglycosides
Acute kidney injury (nephrotoxic)
Ototoxic
name the aminoglycosides
Amikacin (IV) Gentamicin Tobramycin Plazomicin Streptomycin
second line tx of TB?
aminoglycosides - Streptomycin
class of abx that has: Excellent Gram negative coverage including P. aeruginosa along with Synergy against Gram positives
aminoglycosides
indications for prescribing aminoglycosides
Hospital-acquired infections
Endocarditis
TB
Aminoglycosides are NOT often used alone except for treating ____?
UTIs
ADRs for aminoglycosides
nephrotoxicity
MONITOR trough levels
what abx are urinary antiseptics
Nitrofurantoin
(Macrobid; Macrodantin)
Fosfomycin (Monurol)
_______ typically drug of choice to tx UTIs in pregnancy (except after week 38)
Nitrofurantoin
Nitrofurantoin (does /does not??) penetrate ureters.
DOES NOT penetrate ureters
limited to lower UTI infections
coverage of Nitrofurantoin
Enterococcus (VSE & VRE)
GNR
E. coli
ADRs of Nitrofurantoin
CrCl <60 ml/min (RENAL DOSE)
Hepatotoxicity
Pulmonary toxicity
Neuropathy
what abx covers:
Gram (+) aerobes & anaerobes ONLY
MRSA/ VRE
and DOES NOT need to be renally dosed?
Linezolid
ADRS of what abx?
Serotonin syndrome
HTN crisis
Tyramine-containing foods
Thrombocytopenia
Linezolid
indications for prescribing linezolid
Pneumonia
Skin infections
Bacteremia/sepsis
MRSA in SEVERLY compromised kidneys
what do we prescribe for MRSA in SEVERLY compromised kidneys
Linezolid
what abx cannot be used in pneumonia?
daptomycin
binds to lung surfactant
coverage of daptomycin
Gram positives only (including MRSA and VRE)
ADRs of daptomycin
Myalgia
Neuropathy
elevation in CPK
Rhabdomyolysis
indications for prescribing daptomycin
Skin infections
Bacteremia
Endocarditis
Osteomyelitis
besides vanco PO what abx is ONLY used for c. diff?
Fidaxomicin (Dificid) (PO)
Fidaxomicin (Dificid) has a _____ fecal concentration and _____ serum concentration.
high fecal
low serum
One dose of _____ lasts 72-84 hours in bladder!
Fosfomycin (PO)
coverage of Fosfomycin
Enterococcus (VSE, VRE)
Staphylococcus (MSSA, MRSA)
GNR
Pseudomonas
indications for Fosfomycin
UTI – recurrent
Cystitis
indications for Nitrofurantoin
UTI – in pregnant women
Chronic UTI suppression
Cystitis
what would we avoid FQs in children?
avoid in young children due to risk of inappropriate formation of cartilage
Seizures: Risk with all beta-lactams if inappropriately adjusted for _____ function
renal
abx that are Hepatotoxic
nafcillin
oxacillin
fluoroquinolones,
Macrolides (_________): risk of sudden cardiac death, ___ ______
azithro
Qtc prolongation
beta-lactams with highest seizure risk
Cefepime
Fluoroquinolones
Carbapenems
class of abx that cause QTC prolongation
FQs
macrolides (azithro)
what ADR are we most worries about w/ daptomycin? (think what increases?)
increased CK (rhabdomyolysis)
abx casuing photosensitivity
tetracyclines
bactrim
Tx for c. diff
Metronidazole (flagyl) IV or PO
Vancomycin PO only
alternatives: clinda ampicillin amoxicillin FQs cephs
VSE UTI susceptible options
Nitrofurantoin
fosfomycin
Amoxicillin
amoxicillin/clavulanic acid
Doxycycline
VSE Infections Parenteral – susceptible enterococci
Ampicillin (Gold standard)
Penicillin G
Vancomycin
+/- Gentamicin depending on illness severity
abx for VRE
Daptomycin
Linezolid
Tigecycline
Telavancin
May use any of the VSE if susceptibility indicates
PO options for MRSA
Bactrim DS
Clindamycin
Tetracyclines
Linezolid
IV options for MRSA
Vancomycin Daptomycin Linezolid Tigecycline Telavancin Ceftaroline
abx cover pseudomonas
Beta-lactams
Piperacillin/Tazo (Zosyn)
Ceftazadime
Cefepime
Fluoroquinolones (except moxifloxacin)
Aminoglycosides
abx that cover atypicals
Macrolides
tetracyclines
FQs
indication for rifampin
TB - absorbed in CSF
MSSA
MRSA
coverage of rifampin
Gram + (some gram -) MSSA MRSA haemophilus neisseria meningitis
ADR rifampin
myalgia
arthralgia
hyperbilirubinemia
Time-dependent killing
exert optimal bactericidal effect when drug concentrations are maintained above the MIC.
Higher frequency of dosing.
b-lactams
Concentration-dependent killing
achieve increasing bacterial kill with increasing levels of the drug. Continue to have activity even after the antibiotic level falls below the MIC.
Higher doses and lesser frequency.
aminoglycosides
FQs
AUC:MIC
vanco
Time Dependent Drugs should be dosed ___ per day.
3-4 times per day
Beta-lactam antibiotics, such as penicillins and cephalosporins
Concentration Dependent Drugs should be dosed ___ per day.
once- or twice-daily dosing is optimal, to ensure high peak concentrations.
Aminoglycosides and fluoroquinolones
Synergistic drug combo to treat complicated MSSA
nafcillin + gentamicin
____+_____ use is often reserved for prosthetic valve endocarditis or prosthetic joint infections
nafcillin + gentamicin
abx with no dosing adjustments needed
Ceftriaxone
nafcillin
oxacillin
linezolid
MOA of beta-lactams
MOA: Inhibits Penicillin Binding Proteins (PBPs )
Inhibits the cross-linking of peptidoglycan.
Prevents the development of bacterial cell wall.
beta lactams are (concentration / time) dependent and (bactericidal / bacterialstatic) except for _____.
times
Bactericidal
Enterococcus
how are most beta lactams eliminated?
Most are renally eliminated
Except: nafcillin, oxacillin, ceftriaxone
Pcn – resistance (2 ways)
Beta lactamase enzymes inactivate the antibiotic - more common, cleave beta-lactam ring
Modification of the target PBP/low or decreased affinity for Penicillin Binding Protein- MRSA, s. pnuemoniae
how to overcome Streptococcus pneumoniae resistance
high dose amoxicillin
switch to cephalosporin or other agent
Method to overcome beta-lactamase enzymes
Beta Lactamase Inhibitors
MOA of Beta Lactamase Inhibitors
Inhibit some, but not all beta-lactamases
Binds to beta-lactamase, i.e. suicide gene
Prevents the destruction of the parent drug
Most common mechanism of resistance that typically occurs with gram negative organism
beta-lactamase enzymes overcome w beta-lactamase inhibitors
Clavulanic Acid + Amoxicillin (Augmentin)
Sulbactam + Ampicillin (Unasyn)
Tazobactam + Piperacillin ( Zosyn)
it is important to note that Beta Lactamase Inhibitors DO NOT TREAT?
EXTENDED SPECTRUM BETA-LACTAMASES (ESBL) ENTEROBACTERIACIAE.
when treating otitis media what is the antibiotic with additional beta-lactamase coverage recommended if child has already received amoxicillin in past 30 days?
amoxicillin-clavulanate
cephalosporins MOA
Work in a way similar to PCNs by binding to and blocking the activity of enzymes responsible for making peptidoglycan.
So if there is no peptidoglycan – No cell WALL can be produced.
Rash w/ PCN what is the thought process when prescribing?
may consider cephalosporin with decreasing levels of cross reactivity or carbapenem
1st->2nd->3rd generation cephalosporin decrease in level of cross reactivity
Aztreonam - option unless ceftazidime-allergic
how do we go about dosing in a pt w/ a PCN allergy where a beta-lactam is a MUST?
Give test dose ( 1/10th of full dose)
Desensitization
where are FQs concentrated in the body?
Widely distributed in extracellular and intracellular fluids
and are concentrated in prostate, lungs, bile
how are FQs metabolized
in liver and excreted in urine
Moxifloxacin is eliminated in the bile
FQ MOA
concentration dependent bactericidal activity by inhibiting the activity of DNA gyrase and topoisomerase enzymes essential for bacterial DNA replication
what are the respiratory fluoroquinolones
Levofloxacin and Moxifloxacin
macrolide MOA
Primarily Bacteriostatic, by binding to the 50S subunit of the ribosome, they inhibit bacterial protein synthesis.
Relatively poorly absorbed orally
where do tetracyclines penetrate w/in the bodt
Penetrate most body tissues and fluids, concentrated in unobstructed bile.
Does not reach CSF fluids.
Minocycline reaches highest concentration in tears and saliva.
Abx that
Covers Anaerobes ONLY (gram positive and negative - “gold standard”)
Metronidazole (flagyl)
c. diff
b. fragillis
where is bactrim found in the body
Mostly absorbed from GI Tract, Highly concentrated in urine
Binds to serum albumin
what abx is not well absorbed in GI Tract but can be used with Ulcerative Colitis and Inflammatory Bowel Disease because GUT flora metabolize into two compounds
bactrim
Vanco is (bactericidal / static) by inhibiting cell wall synthesis and (is/ is not) readily absorbed in GI tract
bactericidal
is NOT
where does IV vanco penetrate ?
penetrates the bile, pleural, pericardial, synovial and ascetic fluids. Doesn’t easily get to CSF.
MOA of Lincosamides, Oxazolidinones, and Streptgramins
similar action and cover the same bacteria.
Similar to Macrolides, they inhibit protein synthesis by binding to 50S ribosomal subunit.
does clinda or linezolid have gram - coverage?
NO
Good choice for Vanco resisteant staph and MRSA???
Daptomycin
MOA of daptomycin
Cyclic lipopeptide that binds to cell membranes causing rapid depolarization of membrane due to potassium efflux and disruption of the DNA, RNA and protein synthesis.
aminoglycoside MOA
Bactericidal antibiotics that bind to 30S ribsome and inhibit protein synthesis.
conc dependent
“Post Antibiotic Effect”
Residual bactericidal activity persists even after the serum concentration has fallen below the MIC (drug remains intracellular)
where is daptomycin absorbed
Poorly absorbed orally but well absorbed in peritoneum, pleural cavity and joints
what abx is given in intravitreous injections for endopthalmitis
Aminoglycosides
Aminoglycosides are only used as single agents with _____ and ______.
plague and Tuleremia
aminoglycosides that cover pseudomonas
(amikacin > tobramycin > gentamicin)
aminoglycoside syngery for gram (positive or negative)
Gram positive (aerobic, never used as monotherapy)
Synergy - “amp and gent”
Streptomycin in combo with beta-lactams - endocarditis
Unlike most inhibitors of microbial protein synthesis, which are (bacteriocidal /static) , the aminoglycosides are bactericidal /static).
most antimicrobials bacteriostatic
aminoglycosides ARE bactericidal
Used primarily to treat infections caused by aerobic gram-negative bacteria (including Pseudomonas)
aminoglycosides
does RIFAMPIN penetrate CSF?
yes - tx TB
rifampin MOA
Bactericidal antibiotics that inhibits RNA polyermase, suppressing RNA synthesis.
FOSFOMYCIN MOA
Bactericidal antibiotics that inhibits cell wall synthesis.
fosfomycin penetration?
Bladder is the only site where there is adequate concentration of the drug and therefore used only for UTIs
fosfomycin coverage
Coverage against MSSA, MRSA, VRE, VSE, and Pseudomonas
FIDAXOMICIN MOA
Prohibits RNA polymerase, thereby preventing transcription.
Abx use is a major risk factor for C. diff:
Especially administration > ___ antibiotics
Risk of CDI doubles after ___ days of antibiotic therapy
> 3 abx
3 days
