Antibiotics Flashcards
What do these drugs have in common?
penicillins, carbapenems, cephalasporins, vancomycin
they disrupt the cell wall, are bactericidal
When do drugs that weaken the cell wall work on the bacterial cells?
During cell growth and division
Why do drugs that weaken the cell wall not affect human cells?
human cells don’t have a cell wall
prototypical drug
penicillins
Penicillin G
How is Penicillin G administered?
Only given IM or IV. Some forms given as repositories.
repository
drug given as an injection but absorbed slowly over time, maintaining consistent and low levels
Penicillin lethal adverse effect
Allergy
Cross sensitivity with penicillin
cephalosporins
time frame of an allergic reaction
immediate
20-30 minutes
time frame of an allergic reaction
accelerated
1-72 hours
time frame of an allergic reaction
late
days to weeks
treatment for allergic reaction (anaphylactic)
epinephrine
can you give a patient with mild penicillin allergy cephalosporins?
Probably, PO. Avoided with a severe penicillin allergy.
can PCN skin test precipitate an allergic reaction?
yes, testing blood for IgG antibiodies is safer
Can patients be desensitized to PCN?
yes – small dose of penicillin every 60 minutes, with antihistamine support
Penicillin side effects
injection injuries
yes
✔︎ allergic reaction ✔︎ injection injury: pain at injection site, nerve injection, arterial injection (gangrene, necrosis) ✔︎ neurotoxicity ✔︎ Potassium PCN G: risk of hyperkalemia ✘ hepatotoxicity ✘ nephrotoxicity ✘ ototoxicity ✘ photosensitivity ✘ secondary infections
PCN side effects
oto/nephro/hepatotoxicity
no
✔︎ allergic reaction ✔︎ injection injury: pain at injection site, nerve injection, arterial injection (gangrene, necrosis) ✔︎ neurotoxicity ✔︎ Potassium PCN G: risk of hyperkalemia ✘ hepatotoxicity ✘ nephrotoxicity ✘ ototoxicity ✘ photosensitivity ✘ secondary infections
PCN side effects
hyperkalemia
yes
✔︎ allergic reaction ✔︎ injection injury: pain at injection site, nerve injection, arterial injection (gangrene, necrosis) ✔︎ neurotoxicity ✔︎ Potassium PCN G: risk of hyperkalemia ✘ hepatotoxicity ✘ nephrotoxicity ✘ ototoxicity ✘ photosensitivity ✘ secondary infections
PCN side effects
photosensitivity
no
✔︎ allergic reaction ✔︎ injection injury: pain at injection site, nerve injection, arterial injection (gangrene, necrosis) ✔︎ neurotoxicity ✔︎ Potassium PCN G: risk of hyperkalemia ✘ hepatotoxicity ✘ nephrotoxicity ✘ ototoxicity ✘ photosensitivity ✘ secondary infections
PCN side effects
allergic reaction
yes
✔︎ allergic reaction ✔︎ tissue irritation: pain at injection site ✔︎ neurotoxicity ✔︎ Potassium PCN G: risk of hyperkalemia ✔︎ injury from injection site: nerve injection, arterial injection (gangrene, necrosis) ✘ hepatotoxicity ✘ nephrotoxicity ✘ ototoxicity ✘ photosensitivity ✘ secondary infections
beta lactamases
enzyme made by bacteria that breaks down the beta lactam ring present in all penicillins (PCN doesn’t work)
beta lactams
PCNs, cephalasporins, monobactams, carbapenems (not vancomycin)
drug combo for beta-lactamases
amoxicillin + clavulanate
augmentin
drug combo for beta-lactamases
ticarcillin+clavulanate
Timentin
drug combo for beta-lactamases
ampicillin + sublactam
Unasyn
drug combo for beta-lactamases
pipercillin + tazobactam
Zosyn
t/f: drug combos with beta lactamase inhibitors are commonly used
true, broader spectrum
how are cephalosporins classified
by generation: 1-5
increasing generation =
- increasing activity against gram negative bacteria and anaerobes
- increased resistance to beta lactamases
- increased ability to cross BBB
What is the most widely used group of abx?
Cephalosporins – low toxicity
ceph SE
allergic reaction
yes
✔︎ allergic reaction ✔︎ tissue irritation: pain at injection site ✔︎ rash ✔︎ GI distress ✔︎ secondary infections ✘ hepatotoxicity ✘ nephrotoxicity ✘ ototoxicity ✘ photosensitivity
PCN SE
GI distress
no – because always given parenterally
✔︎ neurotoxicity ✔︎ Potassium PCN G: risk of hyperkalemia ✔︎ injury from injection site: nerve injection, arterial injection (gangrene, necrosis) ✘ GI distress ✘ hepatotoxicity ✘ nephrotoxicity ✘ ototoxicity ✘ photosensitivity ✘ secondary infections
ceph SE
tissue irritation
yes
✔︎ allergic reaction ✔︎ tissue irritation: pain at injection site ✔︎ rash ✔︎ GI distress ✔︎ secondary infections ✘ hepatotoxicity ✘ nephrotoxicity ✘ ototoxicity ✘ photosensitivity
ceph SE
GI distress
yes
✔︎ allergic reaction ✔︎ tissue irritation: pain at injection site ✔︎ rash ✔︎ GI distress ✔︎ secondary infections ✘ hepatotoxicity ✘ nephrotoxicity ✘ ototoxicity ✘ photosensitivity
ceph SE
photosensitivity
no ✔︎ allergic reaction ✔︎ tissue irritation: pain at injection site ✔︎ rash ✔︎ GI distress ✔︎ secondary infections ✘ hepatotoxicity ✘ nephrotoxicity ✘ ototoxicity ✘ photosensitivity
ceph SE
rash
yes
✔︎ allergic reaction ✔︎ tissue irritation: pain at injection site ✔︎ rash ✔︎ GI distress ✔︎ secondary infections ✘ hepatotoxicity ✘ nephrotoxicity ✘ ototoxicity ✘ photosensitivity
ceph SE
hepatotoxicity
no
✔︎ allergic reaction ✔︎ tissue irritation: pain at injection site ✔︎ rash ✔︎ GI distress ✔︎ secondary infections ✘ hepatotoxicity ✘ nephrotoxicity ✘ ototoxicity ✘ photosensitivity
ceph SE
nephrotoxicity
no
✔︎ allergic reaction ✔︎ tissue irritation: pain at injection site ✔︎ rash ✔︎ GI distress ✔︎ secondary infections ✘ hepatotoxicity ✘ nephrotoxicity ✘ ototoxicity ✘ photosensitivity
ceph SE
ototoxicity
no
✔︎ allergic reaction ✔︎ tissue irritation: pain at injection site ✔︎ rash ✔︎ GI distress ✔︎ secondary infections ✘ hepatotoxicity ✘ nephrotoxicity ✘ ototoxicity ✘ photosensitivity
ceph SE
photosensitivity
no
✔︎ allergic reaction ✔︎ tissue irritation: pain at injection site ✔︎ rash ✔︎ GI distress ✔︎ secondary infections ✘ hepatotoxicity ✘ nephrotoxicity ✘ ototoxicity ✘ photosensitivity
ceph SE
superinfections
yes
✔︎ allergic reaction ✔︎ tissue irritation: pain at injection site ✔︎ rash ✔︎ GI distress ✔︎ secondary infections ✘ hepatotoxicity ✘ nephrotoxicity ✘ ototoxicity ✘ photosensitivity
ceph SE
Side effects/toxicities BEYOND most common for all abx --- Most common SE for all abx: - GI distress - allergy - secondary infection - tissue irritation - toxicity: nephro, hepato, oto - photosensitivity
rash
PCN SE
Side effects/toxicities BEYOND most common for all abx --- Most common SE for all abx: - GI distress - allergy - secondary infection - tissue irritation - toxicity: nephro, hepato, oto - photosensitivity
- neurotoxicity with high blood levels
- nerve dysfunction with nerve injection
- gangrene/necrosis with arterial injection
- hyperkalemia with Potassium PCN G
PCN G preparation with special consideration
Potassium PCN G: hyperkalemia risk
Cefotetan special considerations
✔︎ increased bleeding risk
✔︎ intolerance to alcohol
✘ eliminated by liver
✘ don’t mix with Lactated Ringers
ceftriaxone special considerations
opposite of cefazolin ✔︎ increased bleeding risk ✘ intolerance to alcohol ✔︎ eliminated by liver ✔︎ don't mix with Lactated Ringers
cefazolin special considerations
Opposite of ceftriaxone ✘ increased bleeding risk ✔︎ intolerance to alcohol ✘ eliminated by liver ✘ don't mix with Lactated Ringers
Increased bleeding risk?
cefotetan, ceftriaxone, cefazolin
✔︎ cefotetan
✔︎ ceftriaxone
✘ cefazolin
Intolerance to alcohol? cefotetan, ceftriaxone, cefazolin
✔︎ cefotetan
✘ ceftriaxone
✔︎ cefazolin
Don’t mix with Lactated Ringers? cefotetan, ceftriaxone, cefazolin
✘ cefotetan
✔︎ ceftriaxone
✘ cefazolin
Eliminated by liver?cefotetan, ceftriaxone, cefazolin
✘ cefotetan
✔︎ ceftriaxone
✘ cefazolin
Carbapenem prototype
Imipenum/Cliastatin: Primaxin
Why are imipenum/cilastatin together?
cilastatin prevents destruction of imipenem by renal enzymes
drug-drug interaction for carbapenem
valproate acid (seizure medication) – can cause lower levels of valproate acid and thus seizures
carbapenem AE
GI distress, allergy
Is vancomycin effective against gram + or gram -?
Gram positive
Is vancomycin used for serious or minor infections?
serious
Vancomycin can cause which toxicities?
Renal and otic
Vancomycin is used in which route, except which case?
IV except PO for c. diff
Vancomycin is the drug of choice for which important infections?
MRSA and sometimes c. diff PO (or flagyl)
tests for renal toxicity
BUN, creatinine, GFR
t/f: we monitor trough levels for vancomycin
True
vancomycin SE
Side effects/toxicities BEYOND most common for all abx --- Most common SE for all abx: - GI distress - allergy - secondary infection - tissue irritation - toxicity: nephro, hepato, oto - photosensitivity
- red man syndrome
- thrombophlebitis (irritating to veins)
How to avoid red man syndrome
infuse SLOWLY over at least 60 minutes
screening for MRSA carriers
nasal swab with PCR
treatment for MRSA carriers
intranasal application of Bactroban or retapamulin
What do all these drugs have in common?
Tetracyclines, macrolides, aminoglycosides,
Inhibit protein synthesis
Tetracycline Side effects/toxicities BEYOND most common for all abx --- Most common SE for all abx: - GI distress - allergy - secondary infection - tissue irritation - toxicity: nephro, hepato, oto - photosensitivity
yellow-brown discoloration of teeth (under 8 and or fetal passed through placenta)
tetracycline SE
GI distress
Yes, AND absorption decreased if given with food.
✔︎ GI distress ✔︎ secondary infections (c. diff) ✔︎ yellow-brown discoloration of teeth ✔︎ photosensitivity ✘ hepatotoxicity ✘ nephrotoxicity ✘ ototoxicity