Pharmacology Ch 87- Aminoglycosides
2 (Trough levels determine the lowest level between doses. Blood is drawn just before the next dose is administered when a divided dose is used or 1 hour before the next dose if a single daily dose is used.)
A nurse is administering a daily dose of tobramycin at 1000. At which time should the nurse obtain the patient's blood sample to determine the trough level? 1 0800 2 0900 3 1130 4 1200
neuromuscular transmission
Aminoglycosdes can inhibit _________ _________, causing flaccid paralysis and potentially fatal respiratory depression
aminoglycosides
MOA: Bactericidal Inhibiting protein synthesis Activity: Serious systemic infections by GRAM NEGATIVE caused by E Coli, serratia, proteus, klebsiella and pseudomonas Adverse Effects ** Ototoxicity: reversible if stopped early - often irreversible however - cochlear and vestibular ** Nephrotoxicity: -- 5-25% of patients -- monitor BUN & creatinine -- Usually reversible Prototype: Gentamicin Others: amikacin, tobramycin
postantibiotic effect
The continued suppression of bacterial growth after an antibiotic serum level has been decreased below Minimal bactericidal concentration
decreased increased
With aminoglycosides, patients with kidney disease should have ______ dosage size and ________ dosing interval, to prevent toxicity.
vancomycin, gentamycin
_______ and _______ both can cause ototoxicity and nephrotoxicity ** need peak and trough levels
3 (Gentamicin causes irreversible ototoxicity, which results in both impaired hearing and disruption of balance. Headache is the first sign of impending vestibular damage (balance) and may last 1 to 2 days. Unsteadiness, vertigo, and dizziness appear after headache.)
A nurse monitors a patient who is receiving an aminoglycoside (gentamicin) for symptoms of vestibular damage. Which finding should the nurse expect the patient to have first? 1 Unsteadiness 2 Vertigo 3 Headache 4 Dizziness
1 (The patient's comment suggests that the person did not hear the instructions. Aminoglycoside antibiotics can cause ototoxicity. The first sign may be tinnitus (ringing in the ears), progressing to loss of high-frequency sounds. Audiometric testing is needed to detect it. Nutrition, confusion, and a family history of dementia do not address the problem of possible hearing loss associated with aminoglycosides.)
A patient is receiving an aminoglycoside (tobramycin) antibiotic. A nurse asks the patient to choose daily meal selections, to which the patient responds, "Oh, dear, I don't want another IV." The nurse makes which assessment about the patient's response? 1 Some hearing loss may have occurred. 2 The confusion is due to the hospital stay. 3 A nutrition consult most likely is needed. 4 The patient has a family history of dementia.
4 (Aminoglycoside-induced nephrotoxicity usually presents as acute tubular necrosis. Symptoms of concern are protein in the urine, dilute urine, and elevation of the serum creatinine and blood urea nitrogen (BUN) levels. WBCs, glucose, and ketones are not specifically related to gentamicin use.)
A patient who is receiving an aminoglycoside (gentamicin) has a urinalysis result with all of these findings. Which finding should a nurse associate most clearly with an adverse effect of gentamicin? 1 White blood cells (WBCs) 2 Glucose 3 Ketones 4 Protein
4 (Flaccid paralysis and impaired breathing are signs of impaired neuromuscular transmission, which may occur with aminoglycosides, especially if they are administered concurrently with a neuromuscular blocking agent. Impaired transmission can be reversed with intravenous infusion of a calcium salt (calcium gluconate). Magnesium sulfate, potassium chloride, and sodium bicarbonate do not reverse impaired neuromuscular transmission caused by aminoglycosides.)
A patient who is receiving an aminoglycoside develops flaccid paralysis and impaired breathing. Which medication does the nurse anticipate administering? 1 Magnesium sulfate [Epsom salt] 2 Potassium chloride [K-Dur] 3 Sodium bicarbonate [Citrocarbonate] 4 Calcium gluconate [Kalcinate]
orally, parenterally
Aminoglycosides are highly polar polycations - so they are not absorbed ______ - they must be administered __________ to treat systemic infection
inner ear, kidneys
Aminoglycosides can cause serious injury to the _____ _____ and _______ - so indications are limited
1 (Aminoglycosides can inhibit neuromuscular transmission, causing flaccid paralysis and potentially fatal respiratory depression. These drugs should be used with extreme caution in patients with myasthenia gravis)
Before administering an aminoglycoside, it is most important for the nurse to assess the patient for a history of what? 1 Myasthenia gravis 2 Asthma 3 Hypertension 4 Diabetes mellitus .
gentamycin
One aminoglycoside, ________ is now commonly used in combo with either vancomycin or a beta lactam antibiotic to treat serious infections with certain gram positive cocci
2 (When trough levels remain elevated, aminoglycosides are unable to diffuse out of inner ear cells, thus exposing the cells to the medication for an extended time. Prolonged exposure (ie, high trough levels), rather than brief exposure to high levels, underlies cellular injury.)
The nurse knows that there is an increased risk of ototoxicity in a patient receiving an aminoglycoside if which level is high? 1 Concentration 2 Trough 3 Peak 4 Dose
amikacin
The principle cause of bacterial resistance is he production of enzymes that can inactivate aminoglycosides - of all of them ______ is the least susceptible to inactivation.
trough
The risk of ototoxicity with aminoglycosides is related primarily to persistently elevated _______ drug levels - First sign of impending COCHLEAR damage is high pitched tinnitus - vestibular damage - Headache - ototoxicity is largely IRREVERSIBLE
2 (Aminoglycosides can inhibit neuromuscular transmission, causing potentially fatal respiratory depression. Patients with myasthenia gravis (MG) are at an increased risk. Deep tendon reflexes, eyelid movement, and muscle strength are important assessments for a patient who has MG, but they are not as important as airway and breathing ability.)
When administering an aminoglycoside to a patient with myasthenia gravis, it is most important for the nurse to assess what? 1 Deep tendon reflexes 2 Breath sounds 3 Eyelid movement 4 Muscle strength
4 (In general, aminoglycosides are poorly absorbed in the gastrointestinal (GI) tract. Neomycin is given orally to suppress bowel flora before surgery of the intestine and is not used parenterally because of its high nephrotoxicity and ototoxicity. Gentamicin, tobramycin, and amikacin are administered parenterally only.)
Which enteral aminoglycoside would the nurse expect to be ordered preoperatively for a patient having intestinal surgery? 1 Gentamicin 2 Tobramycin 3 Amikacin 4 Neomycin
3, 4, 5 (The risk of ototoxicity with aminoglycoside use is related primarily to excessive trough levels. The first sign of impending vestibular damage is headache. The first sign of cochlear damage is tinnitus. The other two statements are true.)
Which statements about ototoxicity and aminoglycosides does the nurse identify as true? (Select all that apply.) 1 The risk of ototoxicity is related primarily to excessive peak levels. 2 The first sign of impending cochlear damage is headache. 3 The first sign of impending vestibular damage is headache. 4 Ototoxicity is largely irreversible. 5 Use of aminoglycosides for less than 10 days is recommended to avoid ototoxicity.
nephrotoxicity
________ in aminoglycosides correlates with: 1. total cumulative dose of aminoglycosides 2. high trough levels - Usually manifests as acute tubular necrosis - injury to kidneys usually reverses after drug discontinued
aminoglycosides
__________ are: - NARROW spectrum used primarily against aerobic gram negative bacilli - DISRUPT PROTEIN SYNTHESIS - causes rapid bacterial death - Bactericidal and concentration dependent
trough, peak
________is drawn before the dose is administered ________ is drawn usually 30 min after the dose is administered IV
aminoglycoside toxicity
nephrotoxicity (esp with cephalosporins), ototoxicity (esp with loop diuretics), teratogen
