Antibiotics Flashcards
bacterial organism classification
aerobic vs. anaerobic
gram-positive vs. gram-negative
atypicals (spirocytes, mycoplasma, chlamydia)
morphology (cocci, bacilli)
empiric treatment
starting and agent prior to knowing the identification or susceptibilities of the organism
selection of antibiotics
identification of infecting organism(s)
antimicrobial susceptibility
site of infection
patient factors
antimicrobial susceptibility
tells which antibiotics will work at certain concentrations-susceptible, intermediate, resistant
site of infection
can have a significant impact-blood brain barrier, joint infections, blood stream infections
patient factors
allergies, kidney/liver function, ADRs
selecting empiric therapy
influenced by site of infection
influenced by host factors-prior infections, social habits, travel history, immune system status, healthcare associated
initial therapy is typically broad-spectrum
unknown what organisms or if there are multiple–> guided by typical and suspected organisms
narrowed upon clinical improvement and culture/sensitivity data
bactericidal
eradicate the organism-‘killing’
bacteriostatic
arrest growth and replication until the host immune system can eliminate the organism-“inhibits”
antibiotic classifications
broad spectrum vs narrow spectrum
MOA classifications
broad spectrum
active against a wide variety of microorganisms- gram positive, gram negative, anaerobe
narrow spectrum
active against only a few species of microorganisms
MOA classifications
cell wall synthesis inhibitors
cell membrane disruption
bactericidal protein synthesis inhibitors
bacteriostatic protein synthesis inhibitors
antimetabolites
bacterial DNA/RNA synthesis or integrity inhibitors
common antibiotic ADRs
antibiotic associated diarrhea
C. difficile diarrhea
allergic reactions/anaphylaxis
fungal superinfections
antibiotic associated diarrhea
GI effects-NVD-typically mild and self-limiting
most antibiotics have at least some degree of causing
disrupts normal gut flora
potentially preventable with probiotics
C. difficile diarrhea
more severe and potentially life-threatening diarrhea caused by C. diff bacteria
overgrowth of a particular harmful bacteria
typically seen with more broad-spectrum antibiotics
drugs that weaken cell walls
penicillins
structures include a beta-lactam ring
penicillins
beta-lactam family includes
penicillins
cephalosporins
monobactam
carbapenems
penicillin’s MOA
disrupts cell wall by binding to penicillin-binding proteins (PBPs) to weaken it and allow bacteria to take up excess water and rupture–>bactericidal
narrow spectrum penicilins: penicillinase sensitive
Penicillin G
Penicillin V
narrow-spectrum penicillins: penicillinase resistant
nafcillin
oxacillin
diclocacillin
broad spectrum penicillins
Ampicillin
Amoxicillin
extended-spectrum penicillin
pipercaillin
penicillin
narrow-spectrum penicillinase-sensitive penicillins
antistaphylococcal penicillins
narrow-spectrum penicillinase-resistant penicillins
aminopenicillins
broad spectrum penicillins
streptococcus species, Neisseria species, many anaerobes, spirocytes, others
narrow-spectrum penicillins-penicillinase sensitive
staphylococcus aureus
narrow-spectrum penicillins-penicillinase resistant
haemophilus influenzae, e. coli, proteus mirabilis, enterococci, neisseria gonorrhoeae
broad-spectrum penicillins
haemophilus influenzae, e. coli, proteus mirabilis, enterococci, neisseria gonorrhoeae, pseudomonas aeruginosa, enterobacter species, proteus (indole positive), bacteroides fragilis, many klebsiella
extended-spectrum penicillin
Unasyn
ampicillin/sulbactam
augmentin
amoxicillin/clavulanic acid
Zosyn
piperacillin/tazobactam
penicillin uses
group A strep pharyngitis
group B strep prophylaxis in OB
syphilis
other susceptible infections
penicillin US boxed warnings
appropriate administration of IM only products-IV administration inappropriately has led to cardiorespiratory arrest and death
penicillin ADRs
allergic reactions-most common of all drug allergies
pain at IV and IM injection sites
What are the antistaphylococcal penicillins?
Nafcillin
Oxacillin
Dicloxacillin
antistaphylococcal penicillins uses
MSSA infections (bacteremia, joint infections, endocarditis)
active against penicillinase-producing strains of staphylococcus (MSSA, S. epidermis)
antistaphylococcal penicillins
NO activity against methicillin-resistant Staphylococcus aureus (MRSA)
antistaphylococcal penicillins
antistaphylococcal penicillins ADRs
allergic reactions-most common of all drug allergies
antistaphylococcal penicillins metabolism/excretion
no renal or hepatic adjustments needed
aminopenicillins uses
group A strep pharyngitis
group B strep prophylaxis in OB
syphilis
increased activity against gram negative bacteria including: Haemophilus influenzae, E. coli, Salmonella, Shigella
widely inactivated by beta-lactamases-but still widely used and effective–> watch for lack of clinical response
aminopenicillins
excellent for cellulitis with anaerobe involvement and aspiration pneumonia
IV Unasyn
aminopenicillins ADRs
allergic reactions-most common of all drug allergies
aminopenicillins metabolism/excretion
renal adjustments needed but no hepatic adjustments needed
Beta-lactamase inhibitors
clavulanic acid (clavulanate)
tazobactam
sulbactam
avibactam
extend microbial spectrum of activity when combined with beta-lactam
ampicillin/sulbactam–> Unasyn
amoxicillin/clavulanic acid–> Augmentin
piperacillin/tazobactam–>Zosyn
give activity back to the penicillinase- or cephalosporinase-sensitive bacteria
beta-lactamase inhibitors
Zosyn uses
broad-spectrum antibiotic in a variety of infections-pneumonia, complicated cellulitis, osteomyelitis, sepsis of unknown origin, catheter related infections
covers MSSA (usually), pseudomonas, and anaerobes and everything in between
Zosyn
lacks: MRSA, atypical bacteria, vancomycin resistant enterococcus (VRE)
Zosyn
primarily used when pseudomonas or other resistant gram negative bacteria is suspected or confirmed
Zosyn
Zosyn ADRs
acute kidney injury-particularly in combination with other nephrotoxic drugs
Zosyn metabolism/excretion
renal adjustments needed but no hepatic adjustments needed
drugs that weaken bacterial cell walls
monobactam carbapenems cephalosporins glycopeptides fosfomycin
monobactam-aztreonam
active against only gram-negative organisms-covers pseudomonas
used in infections with multiple-drug resistance-reserved agent
little to no allergy cross reactivity with penicillins or cephalosporins
monobactam-aztreonam ADRs
neutropenia-particularly in children
increased AST, ALTs
monobactam-aztreonam metabolism/excretion
renal adjustments needed but no hepatic adjustment needed
carbapenems
extremely broad-spectrum antibiotics-restricted at most institutions (reserved for infectious disease consult or positive cultures/susceptibilities)
carbapenems drugs
Doripenem
Imipenem
Meropenem
Ertapenem
Doripenem, Imipenem, Meropenem
cover MSSA to pseudomonas
dosed 2-3 times daily
Ertapenem
no pseudomonas coverage
dosed once daily
great outpatient infusion drug for MDR gram negatives
Doripenem, Imipenem, Meropenem, Ertapenem
all have coverage of anaerobes
most resistant bacteria out there
Carbapenem Resistant Enterobacteriaceae (CRE)
carbapenems have little to no cross-reactivity with
penicillins or cephalosporins (get a decent amount of use because of drug allergies)
carbapenems metabolism/excretion
renal adjustments needed but no hepatic adjustment needed
cephalosporins are the
most widely used group of antibiotics
cephalosporins
beta-lactam antibiotics
structure similar to penicillin
cephalosporin MOA
binds to PDPs, disrupts cell wall synthesis, causing cell lysis
cross-reactivity of cephalosporins to penicillins
1-4%–> more likely that they are allergic to two different antibiotic classes that are truly cross reactive
cephalosporins are comprised of
5 generations with each generation having a slightly unique spectrum of activity
cephalosporin 1st generation uses
surgery prophylaxis, skin-soft tissue infections (Ancef-MSSA), UTIs (Keflex)
cephalosporin 1st generation drugs
cephalexin
cefazolin
Cephalexin
Keflex
Cafazolin
Ancef
3rd generation cephalosporins
Ceftriaxone (Rocephin)
Ceftazidime
Cefdinir
Ceftriaxone
Rocephin
Rocephin uses
*very commonly prescribed in the hospital community acquired pneumonia UTI gram negative bacteria meningitis
Ceftazidime uses
pseudomonas coverage
used in neonates and in peritoneal dialysis for peritonitis
Cefdinir uses
oral agent used in a lot of respiratory bacterial infections
2nd generation cephalosporins
cefuroxime
cefuroxime
oral agent used in many types of infections- a lot of respiratory bacterial infections when cultures never resulted
4th generation cephalosporins
Cefepime
Cefepime
pseudomonal coverage
similar uses to Zosyn except no anaerobic coverage
does not have same risk of nephrotoxicity
5th generation cephalosporins
Ceftaroline
Ceftaroline
rarely used
has MRSA coverage
only cephalosporin that covers MRSA
Ceftaroline
glycopeptides
group of antibiotics with gram positive activity used primarily in MRSA, patient with penicillin allergies, and C. difficile infections- no gram-negative coverage
Glycopeptides MOA
inhibit cell wall synthesis and thus promote bacterial lysis and death
The primary Glycopeptide antibiotic is ____
Vancomycin
vancomycin for C. diff treatment
site of action is topically int he GI tract, so the lack of oral absorption is capitalized on
vancomycin
Vanco
Vanco uses
used frequently in cellulitis cases as it covers staph and strep until cultures/sensitives are resulted and gram-positive bacteria
Vanco ADRs
nephrotoxic-renal failure
red man syndrome
thrombocytopenia
vanco nephrotoxic ADR
dose related and more common with additive nephrotoxic drugs, blood level monitoring and adjustments, monitor serum creatin values
vanco red man syndrome
rapid infusion can cause histamine release- flushing, rash, pruritis, tachycardia, hypotension
Vanomycin (vanco) routes of administration
IV for all indications except C. difficile which is oral
Fosfomycin indications
uncomplicated UTI: covers pseudomonas, GNRs, enterococcus (even VRE); only effective in the bladder
Fosfomycin MOA
inhibits bacterial cell wall synthesis
Fosfomycin ADRs
well tolerates- no ADRs >10%
Fosfomycin metabolism/excretion
no renal or hepatic adjustments but elimination is significantly prolonged in renal impaired patients
tetracyclines
Tetracycline
Demeclocycline (not used as an antibiotic)
Doxycycline
Minocycline
doxycycline common uses
pneumonia
cellulitis
covers MRSA
tetracycline common use
acne
minocycline common use
acne
all tetracyclines common uses
atypical bacteria infections (anthrax, malaria, syphilis, cholera, lyme disease)
gram positive bacteria
gram negative bacteria
atypical bacteria
Tetracyclines MOA
inhibits bacterial protein synthesis
Tetracyclines ADRs
tooth mottling (discolors yellow or brown)-irreversible GI irritation (NVD, epigastric burning) photosensitivity (increased risk of sunburn)
significant absorption chelation can occur and prevents absorption-Ca, Mg, Iron (positive cations) with
tetracyclines
Macrolides
Azithromycin
Erythromycin
Clarithromycin
Macrolides cover
gram positive bacteria
gram negative bacteria
atypical bacteria
no MRSA or pseudomonas
Azithromycin common uses
upper respiratory infections
pneumonia
COPD exacerbations
sinus infections
Erythromycin common uses
acne (topical products)
GI motility in gastroparesis
Clarithromycin common uses
not used often
Macrolides MOA
inhibit bacterial protein synthesis
Azithromycin ADRs
QT prolongation-increased risk of fatal heart rhythms
Macrolides metabolism/excretion
no renal or hepatic adjustments needed
Macrolides significant drug interactions
Clarithromycin is a strong CYP 3A4 inhibitor
clindamycin uses
gram positive bacteria and anaerobic infections
does not cover gram negative bacteria
typically covers MRSA
clindamycin US boxed warnings
C. diff colitis-potentially severe and life-threatening
clindamycin MOA
inhibits bacterial protein synthesis
clindamycin ADRs
antibiotic associated diarrhea and c. diff diarrhea
clindamycin matabolism/excretion
no renal or hepatic adjustments needed
linezolid uses
covers gram positive bacteria only
no gram negative or anaerobes
covers MRSA, VRE
linezolid contraindications
concurrent use or within 2 weeks of monoamine oxidase inhibitors (MAOIs)
linezolid ADRs
diaarhea
linezolid metabolism/excretion
increased risk of serotonin syndrome in combination with SSRIs and SNRIs
aminoglycosides
bactericidal-concentration dependent agents
gentamicin, tobramycin, amikacin, neomycin
aminoglycosides uses
cover gram negatives (including CRE)
severe gram-negative infections
multi-drug resistant organisms
pre-operative antibiotics
aminoglycosides US boxed warnings
nephrotoxicity: typically, irreversible-proper monitoring
ototoxicity: typically, irreversible-individuals with renal dysfunction are more susceptible
pregnancy: can cause fetal harm
aminoglycosides MOA
inhibits bacterial protein synthesis
aminoglycosides metabolism/excretion
pharmacy to dose
peaks for concentration dependent killing, troughs to minimize toxicity
aminoglycoside pharmacokinetics
post-antibiotic effect (PAR): continues killing even after concentration is below MIC
extends interval dosing versus traditional dosing
sulfonamides-sulfamethoxazole/trimethoprim uses
cellulitis, UTI, gram positive infections, MRSA coverage
sulfonamides-sulfamethoxazole/trimethoprim contraindications
history of drug induced-immune thrombocytopenia
sulfonamides-sulfamethoxazole/trimethoprim ADRs
hyperkalemia
hypersensitivity reactions
sulfonamides-sulfamethoxazole/trimethoprim hyperkalemia
blocks sodium channels in the distal nephron-inhibits potassium secretion-potenially fatal
sulfonamides-sulfamethoxazole/trimethoprim hypersensitivity reactions-delayed and immediate
immediate: typical rash, angioedema, anaphylaxis
delayed: severe forms of rashes- Stevens- Johnson Syndrome (SJS), Toxic Epidermal Necrolysis (TEN)
sulfonamides-sulfamethoxazole/trimethoprim metabolism/excretion
renal adjustment needed, no hepatic adjustment needed
other sulfonamide derivative antibiotics
sulfacetamide
silvadene
sulfadiazine
sulfacetamide
topical for acne, bacterial infections, scaling dermatoses, ophthalmic infections
silvadene
silver sulfadiazine
topical for burn treatment
prevention and treatment of wound sepsis
sulfadiazine
toxoplasmosis treatment-not first line
fluoroquinolones indications
cover gram positive bacteria (poorly staphylococcal and no MRSA)
gram negative bacteria (including pseudomonas)
atypical organisms
fluoroquinolones
moxifloxacin
levaquin (levofloxacin)
cipro (ciprofloxacin)
moxifloxacin targets
anaerobes
respiratory fluoroquinolones
Levaquin
Moxifloxacin
non-respiratory fluoroquinolones
Cipro
fluoroquinolones US boxed warnings
serious adverse reactions-tendinitis and tendon rupture, peripheral neuropathy, CNS effects
exacerbation of myasthenia gravis
fluoroquinolones metabolism/excretion
require renal adjustment, no hepatic adjustment
absorption is decreased by cations (Ca, Zn, Al, Mg, Fe, etc.)-give 2hrs before or 6hrs after
fluoroquinolones ADRs
CNS effects/neuroexcitation
QT interval prolongation
tendon rupture/tendinopathy
phototoxicity
fluoroquinolones CNS effects/neuroexcitation
wide range of effects-dizziness/restlessness to confusion, agitation, insomnia, psychosis, hallucinations, suicidal ideation and tendencies-higher possibility in elderly and poor renal function
fluoroquinolones QT interval prolongation
torsades de pointes-higher occurrence in combination with other QT prolonging drugs
fluoroquinolones tendon rupture/tendinopathy
most often the achilles tendon-direct effect on chondrocytes and tenocytes responsible for collagen synthesis
fluoroquinolones phototoxicity
increased sensitivity to the sun
metronidazole
flagyl
flagyl indications
anaerobic bacterial infections, trichomoniasis, surgical prophylaxis, amebiasis
flagyl US boxed warnings
carcinogenic in mice and rats
flagyl contraindications
first trimester pregnancy, alcohol-disulfiram reaction
flagyl ADRs
nausea, headache
metallic taste
flagyl metabolism/excretion
reduce dose by 50% in severe liver impairment, no renal adjustments needed
rifampin indications
tuberculosis, meningococci, eliminations from nasopharynx, many off label uses
never to be used alone in bacterial treatment-resistant develops rapidly
rifampin contraindications
concurrent use of HIV and Hep C drugs
strong inducer of CYP 34A and other CYPs
rifampin ADRs
discolors body fluids-red/orange color
rifampin metabolism/excretion
no dosage adjustments in renal or hepatic dysfunction
nitrofurantoin
macrobid
macrobid indications
UTIs and prophylaxis for recurrent UTIs
macrobid contraindications
anuria, oliguria, or significant impairment of renal function, previous history of cholestatic jaundice or hepatic dysfunction with prior use
macrobid ADRs
well tolerated-none >10%
macrobid metabolism/excretion
avoid use in CrCl <30 mL/min, caution in 30-60 CrCl, no hepatic adjustment