Nursing Pharmacology
Antimicrobial Unit Case Studies
Review the case studies and answer the questions for each case study.
Case Study 1:
The patient is a 46-year-old male who has been diagnosed with a serious wound infection. The culture is
positive for Pseudomonas aeruginosa. Patient’s vitals are: temp 104 F, BP 138/86, HR 99, RR 18. The
provider has prescribed gentamicin (Garamycin) to treat this infection.
1. What two body organs are most at risk for damage due to this antibiotic? How will the nurse assess this
potential damage?
a.
Ears (hearing). This drug is ototoxic
b. Kidneys. This drug is nephrotoxic
2. What assessments should the nurse perform based on the diagnosis and choice of antibiotic?
a. Monitor blood levels (peak/trough)
b.
c.
Monitor temp (should decrease if antibiotic is effective)
Monitor kidney function (I&O, labs)
d. Monitor hearing (8th cranial nerve assessment, presence of tinnitus, balance)
3. The health care provider orders peak and trough levels. What are peak and trough levels and when
should the blood samples be drawn?
Trough levels measure the lowest concentration of the drug present in the
bloodstream. These are drawn just before a dose is given/administered.
Peak levels measure the highest concentration of a drug in the blood stream. In
the case of gentamicin (Garamycin) the peak occurs approx. 30 min after dose is
given IV. So peak level would be scheduled to be drawn 30 min after dose is
given.
It is the nurse’s responsibility to know if a trough/peak has been ordered by the MD and then
coordinate it. So the nurse would call the lab and pharmacy just before the IV dose is hung to
come up and draw the trough. Then the RN would call the lab and pharmacy when the dose
is completely infused so the lab can time a draw for 30 min later. The lab gets the blood
samples – and the pharmacist analyses the levels and works with MD to adjust the next dose
or time for administration if necessary.
Case Study 2:
The patient is a 32-year-old female who has experienced frequent urinary tract infections. She does not
have a health care provider that she sees on a regular basis, but instead relies on the urgent care clinic or
emergency room to meet her health care needs. She is married with 2 children and works in retail as a
salesperson.
Admission data shows the following: temp 101.2 degrees F, pulse 88 bpm, RR 18/min and BP 112/74.
She complains of dysuria, frequency, urgency and suprapubic pain. She reports that her urine is cloudy and
odorous. Lab urinalysis indicates a urinary tract infection and a urine culture is ordered.
The patient is prescribed sulfamethoxazole (Bactrim). The patient states that she shouldn’t need to fill the
prescription right away because she was given that same prescription the last time she had a bladder
infection and she is sure she has some pills left over in her medicine cabinet.
1. What teaching regarding this classification is important?
Complete entire prescription (especially important as she hasn’t done this in the past)
Increase fluids
Take with food or milk to avoid GI upset
Reduces effectiveness of birth control pills – so pt should use a second method
Causes patient to be sensitive to sun and burn easily (wear sunscreen, avoid tanning etc)
2. What is the recommended amount of daily fluid intake while taking this drug and why?
At least 2 liters per day. This prevents crystalluria.
3. What information should you teach her about “saving” medication?
Saving medication leads to drug resistance
If she stops early she may not completely clear infection – requiring re-treatment
Drugs may be less effective or become toxic saved and used past expiration date
4. Why was a urine culture obtained prior to starting the antibiotic?
To determine the bacteria causing the infection and selecting the antibiotic that will work to
treat it. “Match the bug with the drug”
Case Study 3:
The patient is a 16-year-old female being seen by her primary care provider in the clinic for severe
acne. Patient history is unremarkable except for the use of birth control pills. The provider orders tetracycline
500mg PO twice daily for the next ten days, then the patient is to be seen in the clinic by the provider for an
order for a maintenance dose.
1. What side effects are common to this classification?
N/V/D
Abdominal pain
Tooth discoloration (affects fetus or child under age 8)
Superinfection
Sun sensitivity
2. Given the patient’s age, is this an appropriate choice of antibiotic? Explain why.
Yes, she is over the age of 8. This class should not be given to children under age 8 due to
developing adult teeth that can end up permanently discolored. Also should not be given to
pregnant women as it can affect the developing baby teeth buds in the fetus. PREGNANCY TEST
3. What pertinent teaching should the nurse include for this patient?
This medication will interfere with birth control pill effectiveness
Avoid tanning beds, use sunscreen
Don’t take with dairy foods, calcium or antacids (tetracyclines bind with Ca++ and Mg++)
Take all medication as prescribed
Don’t save this medication – when outdated it can become toxic as it decomposes
Case Study 4:
The patient is a 66-year-old male who presents to the clinic. He has a history of hypertension,
hyperlipidemia and Type I diabetes, but is otherwise in good health. He attends a local gym to work out on a
regular basis. He recently scraped his right knee on a piece of gym equipment but didn’t think anything of it
at the time. Two days later he reports that he developed what appeared to be a small raised, reddened and
tender area on the spot where he had scraped his leg. That spot is now increasing in size and draining.
Vitals: 100.2 F – pulse 78- RR 12 – BP 144/82
Home Medications: Insulin, Atenolol, Lovastatin
Physical Assessment: Abscessed scrape on right knee. Area of induration (redness) is approx. 3 cm by 5
cm. Draining white/greenish pus tinged with blood. Warm to touch.
The provider performs an incision and drainage (I&D) and obtains a culture. Culture is positive for MRSA.
1. Which of your prototypes is a drug of choice for treating MRSA?
Vancomycin
2. What “syndrome” is commonly associated with this antibiotic and what symptoms can you expect?
“Red man syndrome”
Symptoms include: Decreased BP, flushing of neck and face
3. What two body systems are most at risk for damage by this antibiotic?
Ears (ototoxic)
Kidneys (nephrotoxic)
4. What assessments should the nurse be doing for this patient because of the diagnosis and choice of
antibiotic?
a. Monitor IV site, administer over 60 min
b. Assess hearing before and during treatment
c. Ensure adequate hydration (2 L fluids/24 hr) if not contraindicated to prevent
nephrotoxicity
d. Monitor blood levels (peak/trough)
Case Study 5:
The patient is a 51-year-old male who was admitted to the hospital for fever. He is status post prosthetic
aortic valve replacement 7 months earlier. His blood cultures were positive for Candida parapsilosis, a
systemic fungal infection. The cardiac surgeon was hesitant to remove the valve and the patient himself
refused to undergo any additional cardiac procedures.
Subsequently the patient is to be started on amphotericin B at 0.7 mg/kg/day via IV to treat the fungal
infection.
1. What routes can this medication be given? What special considerations need to be taken based on your
answer?
Can be IV or topical. This pt has it ordered via IV.
The nurse knows it is important to infuse this drug slowly over a minimum of 30 minutes and use
an IV pump.
2. What serious adverse effects are common to this medication when it is being administered?
More common
Hypotension
Chills/fever
Nausea
Muscle/joint aches
Less common
seizures
parasthesias
3. What other medications can be administered before the amphotericin B is given to help decrease or
prevent these adverse effects?
a. Tylenol (for fever prevention)
b. Antihistamine (like Benadryl) Helps prevent hypotension, allergic reaction symptoms
c.
Antiemetic (to prevent vomiting)
d. Corticosteroids
4. What assessments need to be done while the drug is infusing? While the patient is on the drug?
While infusing:
Monitor IV site
Vitals every 15-30 minutes
I&O
Side effect symptoms
While patient is on the drug:
CBC
EKG
I&O
Vitals
Neuro status
Liver function tests
Renal labs (BUN, creatinine)
5. What two body systems are most at risk for damage by this medication?
Kidneys (nephrotoxic) up to 80% of patients on this drug will have some effect on their kidneys
Liver (hepatotoxic)
Other systems affected: cardiovascular, central nervous system
Case Study 6:
The patient is a 23-year-old with an upcoming month-long environmental study trip planned to a rainforest in
South America. He has been planning this trip since he graduated from college and he is leaving in 3 weeks
with two friends. He has researched the trip and knows about the possible endemic diseases including:
tuberculosis, leishmaniasis, and malaria. After discussing the trip with the healthcare provider (HCP), it is
decided that malaria is the biggest health threat during the trip.
The patient undergoes a complete physical exam and is up to date on all required immunizations. The
provider has ordered chloroquine (Aralen) for the patient.
1.
When does chloroquine (Aralen) therapy need to be initiated in this instance and provide rationale?
Beginning 1-2 weeks prior to travel. He is using the drug as a preventative to malaria. It is taken
once a week. Has a half-life of 3-5 days, so will take longer to build to a therapeutic level.
(Remember that the longer the half-life, the longer it takes to get to a therapeutic level. Also, the
longer the half-life, the longer effects last after the last dose is given)
2.
How long does the patient need to take the chloroquine (Aralen)? Why?
Continue to take drug for 8 weeks after return from travel. Aralen works to destroy the malaria
parasite when it enters the bloodstream by inhibiting DNA replication and interrupting protein
synthesis. Because of the life cycle of the parasite that causes malaria is 10-14 days, it can take
up to 4 weeks to completely rid the body of them.
3. What side effects are associated with chloroquine (Aralen) therapy?
Common
N/V/D
Dizziness, headache
Rash
Blurred vision (needs to call MD if this occurs)
Adverse (an FYI….don’t need to memorize these as are rare!)
Neutropenia
Stevens Johnson syndrome
Seizures
Anaphylaxis
4. Discuss 3 important teaching considerations related to this medication?
If taking for prophylaxis: start 1-2 weeks before travel and continue for 4 weeks after returning
Take with food if GI upset occurs