Chapter 46: Antibiotics Flashcards
AMA
Substance that kills or inhibits the growth of microorganisms such as bacteria, fungi, or protozoans
Antibiotic Agent
Agent kills or inhibits the growth of bacteria
Bacteria are classified as
- Gram + or Gram -
- Shape
- O2 ability
Gram + bacteria
staphylococcus, streptococcus, enterococcus
Gram (+) bacteria (Some babies eat kangaroo pee)
bactericides, escherichia, klebsilla, pseudomonas, salmonella
Aerobic
thrive in an oxygen rich environment
anaerobic
thrive in a non oxygen rich environment
Abx Classes
- Penicillins
- Cephalosporins
- Tetracyclines
- Macrolides
- Aminoglycosides
- Fluroquinolones
- Sulfonamides
- Miscellaneous abx
Action of Abx drugs
affect target organisms structure, metabolism or life cycle
Abx goal
To eliminate pathogen
Bactericidal
Kill bacteria
Bacteriostatic
Slow growth of bacteria
What may abx drugs be used for
prophylactic treatment of people with suppressed or compromised immune systems
Abx considerations
finish all abx
do not share
keep away from children
decrease in OCP and use back up BC
what foods to take and what to avoid
wear medic-alert bracelets if allergic
skin teeth tendons ears kidneys
assess renal/hepatic function esp in elderly 2.2lb/day
persistant diarrhea in children
take probiotics 1-2x/day to counter antibiotic
monitor for hypersensitivity with first dose
make sure pt knows S&S of allergic rxn
most abx best taken on empty stomach
Penicillins most effective against
gram positive bacteria
What allows bacteria to be resistant
beta lactamase or penicillinase
Penicillin prototype drug
Penicillin G potassium
Penicillin G MOA
to kill bacteria by disrupting their cell walls
Penicillin G use
Streptococci, pneumococci, staphylococci, gonorrhoea, syphilis
Penicillin G ADEs
anaphylaxis
D/N/V
pain at injection site
super infections
drug interactions
Role of nurse in penicillin therapy
assess previous reaction to penicillin
avoid cephalosporins if pt has hx of severe penicillin allergy (cross sensitivity) 5-10%
monitor for hyperkalemia and hypernatremia
monitor cardiac status, including ECG changes
Cephalosporins
similar in structure and function to penicillin
have beta lacta ring are bactericidal
cephalosporin prototype drug
cefazolin
Cephalosporin MOA
inhibits cell wall synthesis
Cefazolin uses
gram negative organisms
infections of resp, urinary, skin, biliary, bones, joints, genital, septicaemia, endocarditis infections
Cefazolin ADEs
hypersensitivity
rash
itching
anaphylaxis
D/N/V
pain at site
drug interactions
Role of nurse is cephalosporin therapy
assess for presence or Hx of bleeding disorders (may reduce prothrombin levels)
assess renal and hepatic function (esp in elderly)
assess persistent diarrhea in children
avoid alcohol (can cause disulfiram rxn)
Tetracyclines
some of the broadest spectrums of any abx class
large number of resistant bacterial strains
Tetracyclines drug of choice for
Rocky mt spotted fever
PUD
chlamydial infections
acne
Tetracycline prototype drug
tetracycline
Tetracycline MOA
inhibit bacterial protein synthesis with bacteriostatic effect
Tetracycline Uses
broad spectrum gram + and gram -
Tetracycline ADEs
Superinfections
N/V/D
epigastric burning
discolouration of teeth
photosensitivity
drug interactions
Role of the nurse in tetracycline therapy
contraindicated for pt who are pregnant or lactating
contraindicated in children less than 8 years of age (permanent teeth mottling)
decrease effective of oral contraceptives
increase potential for yeast infection while taking OCP and tetracyclines
use with caution in pts with impaired kidney or liver function
take on empty stomach to increase absorption
photosensitivity may result
do not take with milk products, iron supplements, laxatives, antacids
watch for super infection
Macrolides
safe alternatives to penicillin
broad spectrum so superinfections may occur
Macrolides prototype drug
erythromycin
Erythromycin MOA
inhibit protein synthesis by binding to bacterial ribosome
Erythromycin Uses
effective against most gram positive and gram negative bacteria
Are macrolides bactericidal or bacteriostatic
Bacteriostatic at low doses
bactericidal at high doses
Erythromycin ADEs
hepatotoxicity
N/V
abdominal cramping
Role of the nurse in macrolide therapy
watch liver with EES erythromycin estolate
multiple drug-drug interactions occur with macrolides (CYP)
monitor because this exacerbates heart disease
cause a metallic taste in mouth
Aminoglycosides
Reserved for serious systemic infections caused by aerobic gram negative bacteria
more toxic than most abx
potential to cause serious ADEs
black sheep last names
Aminoglycoside prototype
Gentamicin
gentamicin MOA
broad spectrum bactericidal (inhibit bacterial protein synthesis)
Gentamicin Use
serious urinay, resp, nervous, GI infections
Gentamicin ADEs
Ototoxicity (worse w lassie)
Nephrotoxicity (worse with Zovirax)
neuromuscular blockage
Role of the nurse in amino glycoside therapy
hearing loss monitor
neuromuscular function impairment
increase fluid intake unless contraindicated
caution if hypersensitive to sulfites
Fluoroquinolone
decreased 90% if taken with multivitamins or minerals such as calcium, magnesium, iron or zinc ions (tetras 50%)
NO TEENAGERS OR ATHLETES
can cause C diff
QT prolongation
Fluoroquinolones prototype drug
Ciprofloxacin
Ciprofloxacin MOA
inhibits bacterial replication and DNA repair
Ciprofloxacin Uses
resp bone joint GI opthlamaic sinitius infections
Ciprofloxacin ADEs
GI
headache
dizziness
photosensitivity
dysrhythmias
liver failure
CNS disturbances (1-8%)
Role of the nurse in fluoroquinolone therapy
decreased WBC
monitor pts with liver and renal dysfunction
drug may cause dizziness and lightheadedness
may cause photophobia
may affect tendons
monitor for dysrhytmias
crosses into breastmilk
Sulfonamides
widespread use has led to increased resistance
used in combo to treat UTIs
anti-inflammatory properties can help with RA and ulcerative colitis
teratogenic
do not take while breastfeeding or pregnant
caution with 1st dose
Sulfonamide prototype drug
Trimethoprim-sulfamethoxazole (tmp/smz)
tmp/smz MOA
to kill bacteria by inhibiting bacterial metabolism of folic acid
tmp/smz uses
urinary, pneumocystis, pneumonia, shigella, bronchitis
tmp/smz ADEs
skin rashes
N/V
agranulocytosis
thrombocytopenia
photosensitivity
Role of nurse in sulfonamide therapy
assess for anemia or other hematological disorders
assessed renal function (can increase risk for crystaluria)
ensure back up BC used
contraindicated in pts w Hx of SJS
how to decrease effects of photosensitivity
Carbapenems
antibiotics used for the treatment of infections known or suspected to be caused by MDR bacteria
used in hospitalized ppl
low incidence of ADEs
Glycopeptides
vancomycin
breaks down amino acid wall
used to treat C diff
Glycosamides
clindamycin (IV only)
can cause C diff
Miscellaneous Prototype
vancomycin
vancomycin MOA
bactericidal, inhibits cell wall synthesis
vancomycin Uses
reserved for severe or resistant gram positive infection, effective for MRSA and C diff
Vancomycin ADEs
ototoxicity, nephrotoxicity, red man syndrome, confusion/hallucinations, anaphylaxis
Nitroimidazoles
flagyl
treats anaerobic bacterial infections and protozoal infections
inhibits DNA synthesis
watch liver
Nitroimidazoles ADEs
dark red/brown urine
metallic taste in mouth
seizures
N/V/D
SJS
Daptomycin
A lipopeptide antibiotic used in tat of systemic and life threatening infections caused by gram positive organisms
useful in treating MDR infections
Acquired resistance
as abx are used, they destroy sensitive bacteria
ARO’s
CBO
ESBL
MRSA
VRE
VRSA
Multidrug resistant
when an organism is resistant to more than one drug
What to teach patients about acquired resistance
teach pts to take full course
do not save abx or share with others
abx do not treat viral infections
over prescribing has a lead to ARO
C&S prior to treatment id preferable
Culture and sensitivity testing
ideally lab test are conducted prior to anti-infective therapy
organisms are grown in the laboratory
several abx are tested for effectiveness
may take days or weeks for results
using a specific abx may decrease antagonism and resistance
superinfections
secondary infections that occur when too many host flora are killed by abx
Host flora
Stop growth of pathogenic organisms by
- making antibacterial substances
- competing for space and nutrients
Signs and symptoms of superinfections
diarrhea (C diff)
bladder pain and painful urination (e coli)
abnormal vaginal discharge (yeast candida)
red rash with satellite lesions (yeast candida)
When should you suspect C difficile
- 3 or more episodes of unformed stool in 24 hours and elevated WBC
- Diarrhea during or up to 6 weeks after antibiotic therapy
- Diarrhea following hospital discharge or 72 hours after admission
why should all antidiarrheals, antibiotics and proton pump inhibitors be stopped?
Antidiarrheal may mask tat failure or worsening diarrhea
overuse of antibiotic therapy for co existing conditions may lead to C diff
proton pump inhibitors may increase risk for C diff
If antibiotic overuse can lead to C difficile, then why is it ordered for treatment
for mild to moderate C diff, PO/NG routes mean it will stay longer in the gut thus provide the best treatment - IV routes are not as effective
once it become severe, oral or rectal vancomycin is the best treatment
