Chapter 39: Antibiotics Part 2 pg 633 Flashcards
multidrug-resistant organisms include….
MRSA,
VRE, (found in UTI)
and ESBL-
and KPC-producing organisms
minimum inhibitory concentration (MIC)
is a measure of the lowest concentration of drug needed to
kill a certain standard amount of bacteria.
time-dependent killing
the amount of
time the drug is above the MIC is critical for maximal bacterial
kill.
concentration-
dependent killing;
achieving a drug plasma
concentration that is a certain level above the MIC, even for
a brief period of time, results in the most effective bacterial
kill
trough (lowest) levels are
routinely measured
to ensure adequate renal clearance of the drug and avoid
toxicity
Samples for measurement
of peak levels and trough
peak levels are drawn 30 minutes after a 30-minute
infusion, and samples for measurement of trough levels are
drawn just before the next dose
postantibiotic effect.
This is a period of
continued bacterial growth suppression that occurs after shortterm
antibiotic exposure, as in once-daily aminoglycoside dosing
Aminoglycosides are never used alone
to treat gram-positive
infections.
Aminoglycosides are inactive against
fungi, viruses, and most
anaerobic bacteria.
Aminoglycosides are very potent antibiotics and are capable of
potentially serious toxicities, especially to the kidneys (nephrotoxicity)
and to the ears (ototoxicity), in which they can affect
hearing and balance functions
Currently available aminoglycosides include
amikacin,
gentamicin, kanamycin, neomycin, streptomycin, and tobramycin.
Neomycin is most commonly used for bacterial decontamination
of the GI tract
In hepatic encephalopathy, the
drug helps reduce the number of ammonia-producing bacteria
in the GI tract.
Currently available quinolone (fluoroquinolones) antibiotics include
include norfloxacin, ciprofloxacin,
levofloxacin, and moxifloxacin.
black box warning
increased risk
of tendinitis and tendon rupture
several drugs that interact with quinolones
antacids, calcium, magnesium,
iron, zinc preparations or sucralfate causes a reduction
in the oral absorption of the quinolone. Patients need to
take the interacting drugs at least 1 hour before or after taking
quinolones.
red man syndrome
characterized by flushing
and/or itching of the head, face, neck, and upper trunk area
Daptomycin (Cubicin
lipopeptides. Its mechanism of action is not completely
known, but it binds to gram-positive cells in a calcium-dependent
process and disrupts the cell membrane potential
Colistimethate (Coly-Mycin) is a polypeptide antibiotic
often as one of the only drugs available to
treat KPC.
Diagnostic and
laboratory studies that may be ordered include the following:
(1) AST and ALT levels for assessing liver function; (2)
urinalysis, BUN, and serum creatinine levels for assessing
renal function; (3) ECG, echocardiography, ultrasonography,
and/or cardiac enzyme levels for assessing cardiac
function; (4) culture and sensitivity of infected tissue or
blood samples for assessing sensitivity of the bacteria to the
antibiotic; and (5) white blood cell (WBC) count, hemoglobin
level, hematocrit, RBC count, platelet count, and clotting
values for baseline blood count levels.
aminoglycosides, assess for
hypersensitivity and preexisting conditions. known for their ototoxicity and nephrotoxicity perform baseline hearing tests and assessment of vestibular function
linezolid
possible serotonin syndrome
assess for intake of tyraminecontaining
foods (e.g., aged cheese or wine, soy sauce, and
smoked fish or meat) because of the risk of elevated blood
pressure.
Dosing is adjusted based on estimates
of creatinine clearance calculated
to monitor patient’s renal function and thus helps to prevent toxicity.
Keep in
mind the following special considerations for gentamicin
(1) Intramuscular: Give deeply and slowly into muscle mass
(ventrogluteal) to minimize discomfort; and (2) Intravenous:
Check for incompatibilities with other drugs, and give
only clear or very slightly yellow solutions that have been
diluted with either normal saline (NS) or D5W, infusing at
the correct rate.
Quinolones,
not to take these medications
with antacids, iron, zinc preparations, multivitamins, or sucralfate
because the absorption of the antibiotic will be decreased
take calcium or mag meds 1 hour before or after
clindamycin topical forms
advise patients to avoid the
simultaneous use of peeling or abrasive acne products, soaps,
or alcohol-containing cosmetics to prevent cumulative effects;
however, some products combine clindamycin with anti-acne
medications (e.g., Acayna)
Linezolid take with….
and avoid….
given with food or milk
Foods
that may increase blood pressure aged cheeses, wine, soy sauce,
smoked meats or fish, and sauerkraut due to their tyramine
content
Nitrofurantoin
given
with plenty of fluids, food, or milk to decrease GI upset. Do
not crush tablets to help prevent tooth staining and GI upset
superinfection, hepatotoxicity and peropheral neuropathy
The nurse will question the use of a floroquinolone antibiotic in a patient already prescribed which medication?
amidarone
Dangerous cardiac dysrhythmias are more likely to occur when quinolones are taken by patients receiving class IA and class III antiarrhythmic drugs such as disopyramide and amiodarone. For this reason, such drug combinations should be avoided.
When planning care for a patient receiving once-daily intravenous gentamicin therapy, the nurse schedules a trough drug level to be drawn
Trough serum drug levels should be drawn at least 8 to 12 hours after the medication is infused.
A patient is prescribed metronidazole (Flagyl) for a gynecologic infection, and she provides a list of medications she takes routinely to the nurse. Which medication would lead the nurse to question the order for Flagyl?
Flagyl is known to cause and increase in neurologic-associated medications and specifically can lead to lithium toxicity. A patient who reports taking lithium should be a red flag for the nurse to alert the provider due to the potential significant interaction.
Quinolones are a class of antibiotics known for several significant complications
Quinolones are not used in prepubescent children due to the risk of cartilage development issues. Quinolones may also cause a cardiac effect that involves prolongation of the QT interval on the electrocardiogram. The use of these medications can result in tendonitis or rupture tendons in adults. Nephrotoxicity and ototoxicity are not associated with quinolones.
