Antibiotics 1 Flashcards
drugs that weaken bacterial cell wall (4)
- penicillin
- cephalosporins
- Carbapenems
- other: vancomycin
cytolysis
cell wall wall disruption
cytolysis, what do the abx do?
drugs cause cytolysis
cell takes on H2O
cell burst
BACTERIACIDAL
When does cytolysis occur?
happens when bacteria is undergoing growth and division b/c thats when binding proteins are expressed
why don’t abx cause cytolysis in our normal cells?
- normal human cells dont have cell walls
- bacterial cells have cell walls
Penicillin prototype
Penicillin G
Penicillin G discovered in
1928
what is a penicillin repository?
- repository = absorbs slowly over a week or several weeks
result: produces blood levls that are persistent but low
How is penicillin given?
Usually IV or IM b/c penicillin is destroyed by stomach
Is penicillin toxic?
1 of the least toxic and safest antibiotics
4 kinds of penicillin salts
- Potassium Penicillin G
- Procaine Penicillin
- Benzathine Penicillin
- Sodium Penicillin
Penicillins that are repositories
Procaine Penicillin and Benzathine Penicillin
What to watch with Potassium Penicillin G and how is it given
Potassium, IV
What to watch with Sodium Penicillin?
Na
Most common cause of drug allergies
Penicillin G (.4-7% have allergic rxn)
Types of allergic reactions
- Immediate (2-30 min)
- accelerated (1-72 hr)
- late (days-weeks)
treatment for allergic rxn
epinephrine
-resp support, check O2 status, antihistamine
symptoms of anaphylaxis
- laryngeal edema
- hypotension
- broncho constriction
Penicillins have cross sensitivity to
Cephalosporins
1% of ppl allergic to penicillin also allergic to cephalosporins
Mild Penicillin Allergy , cephalosporins?
oral cephalosporin’s okay
Severe penicillin allergy, cephalosporin?
no cephalosporin
2 ways to check for penicillin allergy, which is safer
- skin test which can precipitate allergic rxn
- check for IgG antibodies = safest
desensitization to penicllin
done in ICU, give small dose every hours until up to full dose
-for patients who have to have pnc
special consideration with penicillin injection
-very viscose, use large bore (18) needle
what can happen if PCN injected into nerve?
-sensory nerve dysfxn
high blood levels of PCN cause
-neurotoxicity (seizure, hallucination)
what happens if inject PCN into artery
- necrosis, gangrene
- –> Aspirate!
High risk of what with Potassium PCN G
-hyperkalemia
how do you identify penicillin?
-ends in cillin
Beta lactamases, what are they?
-enzymes produced by bacteria itself that breaks down the beta lactam ring that is present in all PCN
what causes PCN to be inactive?
Beta lactamases
How are Beta lactamases transmitted?
-ability can be passed from one bacteria to another thru DNA
PCN drug combos- what do you combine with?
combine antibiotic with beta lactamase inhibitor
which has more adverse rxn- penicillin or beta lactamase inhibitor
- penicillin has adverse effects
- beta lactamase inhibitors have minimal toxicity
Benefit of penicillin with beta lactamase inhibitor
increase spectrum of covereage
allow penicillin to work
zosyn, what is it? How long infuse?
- penicillin with beta lactamase inhibitor
- IV infuse over 4 hours to extend the minimum inhibitory concentration and kills more bacteria
how do cephalosporins fxn
weaken bacterial cell wall
-bacteriacidal
3 types of beta lactam antibiotics
- penicillin
- cephalosporin
- carbapenems
most widely used group of abx
cephalosporins
-very low toxicity
cephalosporin route
how many are oral?
IV or IM
-only 10 are oral
classification of cephalosporins
generation 1-5
5= stronger, better med
class 5 cephalosporin
more able to fight gram - and anaerobic bac
increase resistance to destruction by beta lactamases
increase ability to reach cerebrospinal fluid
identifying cephalosporins
start with “ceph” or “cef”
Adverse effects of cephalsporins
1 = allergic (cross sensitivity with PCN)
#2= rash
GI distress
IM injection painful
2 cephalosporins with increase risk of bleeding
- cefotetan
- ceftriaxone
2 cephalosporins that have alcohol intolerance
- cefotetan
- cefazolin
ceftriaxone
- increase bleeding risk
- dont mix with lactated ringers
- eliminated by liver ( not given with liver disorder)
disulfram effect
-with alcohol use makes you feel horrible
2 abx: cefotetan, cefazolin
carbapenems fxn
- weaken bacterial cell wall
- bacterialcidal
carbapenem prototype
-impipenum/cilastatin
why put imipenum and cilastatin together?
-prevent destruction of imipenum by renal enzymes
imipenum and cilastatin route
IV or IM
identifying carbapenums
ends in “penum”
imipenum and cilastatin adverse effects
- GI distress
- Allergy
imipenum and cilastatin drug drug interaction
- decrease effectiveness of valproate acid (antiseizure med)
- –>increase seizures
vancomycin fxn
weakens bacterial cell well
- bacteriacidal
- NOT A BETA LACTAM
- -> inhibits synthesis of bacterial cell wall
Vancomycin treats
- C Diff
- MRSA
- used for serious, only Gram + infections
Vancomycin route and infusion rate
- IV - infuse over 60 minute
- *Oral for C Diff
Vancomycin ADR
- Renal Toxicity
- Ototoxicity
- red man syndrome
- thrombophlebitis
Vancomycin labs- trough level?
-monitor trough level
15-20 mcg/mL
Vancomycin Renal toxicity
- monitor Creatinine/ BUN/GFR
- don’t give other nephrotoxic meds
- if already decrease kidney fxn give renal dosing
Vancomycin Ototoxicity
- hearing loss that is reversible
- occurs with patients with prolonged treatment over several weaks
Vancomycin and red man syndrome
- happens if vancomycin infused too fast <60 min
- red from waist up, flush, rash, pruritis, tachycardia, hypotension
Vancomycin and Thrombophlebitis
- veins irritated and inflamed resulting in loss of IV site
- put in central line to avoid irritation in peripheral veins
MRSA active infection vs carrier
- active infection: IV vancomycin
- carrier: nasal swab PCR, intranasal application of mupirocin or retapamulin
MRSA carriers concerns
-can become active if immunocompromised
