chapter 38 Antibiotics Part 1 Flashcards
Bactericidal antibiotics
Antibiotics that kill bacteria
Bacteriostatic Antibiotics
Antibiotics that do not actually kill bacterial but rather inhibit their growth
The administration of antibiotic based on known results of culture and sensitivity testing identifying the pathogen causing infection
Definitive therapy
The administration of antibiotics based on the practitioner’s judgment of the pathogens most likely to be causing an apparent infection; it involves the presumptive treatment of an infection to avoid treatment delay before specific culture information has been obtained
Empiric therapy
Antibiotic taken before anticipated exposure to an infectious organism in an effort to prevent the development of infection
prophylactic antibiotic therapy
Pseudomembranous colitis
A necrotizing inflammatory bowel condition that is often associated with antibiotic therapy. It also term antibiotic-associated colitis. This happens because antibiotics disrupt the normal gut flora and can cause an overgrowth of Clostridium difficile.
Antibiotic treatment that is ineffective in treating, a given infection. Possible causes include inappropriate drug therapy, insufficient drug dosing, and bacterial drug resistance
Subtherapeutic
antibiotic therapy that results in sufficient concentrations of the drug in the blood or other tissues to render it effective against specific bacterial pathogens
Therapeutic
Superinfection
- An infection occurring during antimicrobial treatment for another infection, resulting from overgrowth of an organism not susceptible to the antibiotic used
- A secondary microbial infection that occurs in addition to an earlier primary infection often due to weakening of the patient’s immune system function by the first infection
MOA of Sulfonamides
- Inhibit bacteria growth (bacteriostatic)
2. prevent bacteria synthesis of folic acid
What are the indications of Sulfonamides
- work against both gram-positive and gram-negative organisms
- Achieve very high concentrations in the kidneys, through which they are elminated.
- Treatment of UTIs, respiratory tract infections.
- prophylaxis and treatment of opportunistic infections in patients with HIV infection
- Tx of Stenotrophomonas maltophilia
- Tx for outpatient Staphylococcus infections
Use of sulfonamides is contraindicated?
Known drug allergy to sulfonamides
chemically related drugs such as; sulfonylureas, thiazide and loop diuretics, carbonic anhydrase inhibitors
cyclooxygenase-2 inhibitor celecoxib (celebrex)
Adverse Effects of Sulfonamide drugs
- common cause of allergic reaction
- delayed cutaneous reactions (fever, rash: morbilliform eruptions, erythema multiforme, or toxic epidermal necrolysis)
- photosensitivity, mucocutaneous, GI, hepatic, renal and hematologic complications.
Medications which interact with Sulfonamides
potentiate the hypoglycemic effects of sulfonylureas in diabetes Tx
toxic effects of phenytoin, warfarin
cyclosporine-induced nephrotoxicity
reduce the efficacy of oral contraceptives
Co-trimoxazole (Bactrim)
a fixed-combination drug product
5:1 ration of sulfamethoxazole to trimethoprim
available in both oral and injectable dosage forms.
A person is normally able to remain healthy and resistant to infectious microorganisms because of?
existence of certain host defenses.
assessment for patient taking sulfonamides
drug allergies to sulfa-type drugs (sulfonylureas) and thiazide diuretics.
skin assessment to look for Stevens-Johnson syndrome.
Red blood cell counts (anemias)
Renal function because of crystalluria
assessments for patient taking penicillins
history of asthma sensitivity to multiple allergens aspirin allergy sensitivity to cephalosporins procaine hypersensitivity neurologic, abdominal and bowel Na and K assessment immediate accelerated or delayed allergic reaction superinfections (colitis)
carbapenems assessments
neurologic functioning
seizure disorders
tremors
abdomen and GI functioning
assessments for patient taking cephalosporins
allergy to penicillins-cross-sensitivity
CBC, bleeding and clotting times
severe diarrhea, bloody stools and abdominal pain
Tetracyclines assessments
culture and sensitivity
whitish sore patches on the oral mucosa (due to candidiasis or yeast infection.
vaginal itching, pain and cottage cheese like discharge (vaginal candidiasis)
superinfections
macrolides assessments
cardiac function
renal and liver function
concurrent use with warfarin
contraceptives use
implementation for macrolides
should not be given with or immediately before or after fruit juices to avoid interaction with the drug.
patient should report severe rash, itching, hives, difficulty swallowing, jaundice, dark urine and or pale stools to the prescriber immediately
implementation for tetracyclines
photosensitivity-avoid sun exposures and tanning bed.
oral doses should be given with at least 8 oz of fluids and food to minimize GI upset
should not be given with dairy products, antacids, sodium bicarbonate, kaolin or pectin or iron.
The interacting foods and drugs may be given 2 hours before or 3 hours after the tetracycline.
patient should report abdominal pain, N/V visual changes and or jaundice.
implementation of sulfonamides
should always be taken with forcing of fluids (2000 to 3000 mL/24 hr) to prevent drug related crystalluria.
oral dosage forms should be taken with food to minimize GI upset.
implementation of penicillins
take oral with at least 6 oz of water (no juices)
Penicillins V, amoxicillin, and amoxicillin/clavulanate should be taken with water 1 hour before or 2 hours to maximize absorption.
should anaphylactic reaction occurs, epinephrine and o2 should be available at all times.
foods that may help prevent superinfections
yogurt
buttermilk
kefir
probiotics
which beverages should be avoided when taken penicillins
caffeine-containing beverages citrus fruit cola beverages fruit juices tomato juice
what is the most common symptom of C. difficile colitis?
watery diarrhea
abdominal pain
fever
What are the broad group of beta-lactam antibiotics
penicillins
cephalosporins
carbapenems
monobactams
what are the indications for penicillins?
prevention and treatment on infections caused by susceptible bacteria.
gram-positive
The extended spectrum have excellent gram-postive, gram-negative and anaerobic coverage.
Which of the penicillins are used to treat many hospital associated infections such as pneumonia, intraabdominal infections and sepsis
piperacillin/tazobactam (Zosyn)
Contraindications for penicillins
drug allergy
it is important to note the drug trade names, because they do not always end in “cillin” (Zosyn, Augmentin, Timentin, Unasyn)
bacterial that have acquired the capacity to produce enzymes capable of destroying penicillins
beta-lactamases
penicillinases
what are the four penicillins subgroups
natural penicillins ( Penicillin G and V)
penicillinase-resistant penicillins (cloxcillin, oxacillin)
aminopenicillins (amoxicillin, ampicillin)
extended-spectrum penicillins (ticarcillin, carbenicillin, piperacillin)
Most common reactions to penicillins
urticaria pruritus angioedema idiosyncratic reactions such as; maculopapular eruption eosinophilia Stevens-Johnson syndrome exfoliative dermatitis
Which patient should not receive cephalosporins because of allergic reactions to penicillins
patients with a history of throat swelling or hives
which generation of the cephalosporins has anaerobic coverage
second generation drugs.
A person who has allergic reaction to penicillin may also have allergic reaction to a cephalosporin. True or false
True
cross-sensitivity
what are some adverse effects of cephalosporins
mild diarrhea abdominal cramps rash pruritus redness edema
The use of cephalosporins are contraindicated in patients
who have shown a hypersensitivity to them.
patient with a history of life threatening allergic reaction to penicillins
first generation cephalosporins
active against gram positive bacteria Eg. cefadroxil cefazolin(Ancef) cephalexin (Keflex) cephradine
use of Cefazonlin (Ancef)
surgical prophylaxis
susceptible staphylococcal infections
gram-positive
which antibiotic will be a good prophylactic in patients undergoing abdominal surgery?
second generation cephalosporin -cefoxitin (Mefoxin)
it provides excellent gram-positive and gram-negative coverage.
it can effectively kill intestinal bacterial, including anaerobes.
A third-generation cephalosporins used to Tx meningitis
Ceftriaxone (Rocephin)
it able to pass easily through the blood brain barrier
should not be given to hyperbilirubinemic and patients with severe liver dysfunction.
should not be administered with calcium infusions.
indication for fourth generation cephalosporin cefepime (Maxipime)
Tx of uncomplicated and complicated UTIs
skin infections
pneumonia
Carbapenems
bactericidal
beta-lactam antibiotics
hazard is drug-induced seizure activity
Monobactams
synthetic beta-lactam
active against aerobic gram-negative (eg, E.coli, klebsiella, pseudomonas).
Tx of moderately severe systemic infections and UTIs.
combined with other antibiotics for the Tx of intraabdominal and gynecologic infections.
advantage of preserving normal gram-positive and anaerobic flora.
what is an advantage in using monobactams
it preserves the normal gram-positive and anaerobic flora.
Common adverse effects of monobactams
rash
N/V
diarrhea
What are some indications for macrolides
mild to moderate upper and lower respiratory tract infections
STDs
diabetic gastroparesis
mycobacterium avium-intracellulare complex infections
active ulcer associated with Helicobacter pylori infection
Adverse effects of macrolide
rash, pruritus, urticaria, thrombophlebitis
hearing loss, tinnitus
stomatitis, cholestatic, jaundice, N/V, hypatotoxicity
palpitations, chest pain
Drug interactions with macrolides
carbamazepine, cyclosporine, digoxin, theophylline and warfarin
oral contraceptives
clarithromycin and erythromycin should not be used with moxifloxacin, pimozide, thioridazine.
simvastatin or lovastatin.
why are Clarithromycin and erythromycin not given with moxifloxacin, pimozide, thioridazine
because malignant dysrhythmias can occur
indications for Tetracyclines
acne
STDs
Rickettsia
Contraindications for tetracyclines
drug allergy
pregnant and nursing women
should not be given to children younger than 8 years
Adverse effects of tetracyclines
discoloration of permanent teeth and tooth enamel hypoplasia
photosensitivity (taking demeclocycline)
alteration of the intestinal and vaginal flora (vaginal candidiasis)
thrombocytopenia
hemolytic anemia
exacerbation of systemic lupus erythematosus
GI upset, enterocolitis and maculopapular rash
Tetracyclines interactions
antacids antidiarrheal drugs dairy products calcium enteral feedings iron preparations oral anticoagulants bactericidal antibiotics oral contraceptives
what is the most serious adverse effect associated with imipenem-cilastatin?
seizures
what should be the nurse’s best action when a patient list “penicillin” as one of his allergies?
careful assessment of the patient’s description of what happened when he had the allergic response.
notify the prescriber of the patient’s allergy and response.
what is the rational behind the use of tazobactam with piperacillin in Zosyn
Tazobactam is a beta-lactamase inhibitor that inactivates the beta-lactamase enzyme.
using it along with the piperacillin make penicillin more effective against infection.
