antibiotics and anti-infectives ?'s

Question 1

A nurse is preparing to administer the first dose of piperacillin/tazobactam to a patient in an infusion
clinic. The nurse should take which of the following precautions?
A. Ask the patient about past allergic reactions to penicillins.
B. Ask the patient about past allergic reactions to aminoglycosides.
C. Mix the piperacillin/tazobactam with lidocaine to reduce pain of infusion.
D. Instruct the patient to eat a snack to decrease stomach upset from piperacillin/tazobactam.

Answer 1

Correct Answer: A. Ask the patient about past allergic reactions to penicillins.

Explanation: Piperacillin is a penicillin antibiotic, and there is a risk of allergic reactions in patients with a history of penicillin allergies. While asking about aminoglycosides (Option B) is relevant for certain interactions or concerns, it’s not the primary precaution in this case. Mixing the medication with lidocaine (Option C) is not appropriate for infusion preparations, and instructing the patient to eat a snack (Option D) is unnecessary as piperacillin/tazobactam can typically be administered on an empty stomach.

Question 2

A woman is to receive amoxicillin–clavulanate 500 mg PO every 8 hours for bronchitis. The nurse
retrieves two 250-mg tablets from the medication cart. This is incorrect for which of the following
reasons?
A. The amount of sulbactam in amoxicillin–clavulanate 250 mg is 62.5 mg per tablet, twice the
intended amount.
B. This provides twice the intended dose of clavulanate.
C. The 250-mg tablets have less absorption than the 500-mg tablets.
D. Administration of amoxicillin–clavulanate is only intravenous, so selecting tablets means that the
wrong drug is being administered.

Answer 2

Correct Answer: B. This provides twice the intended dose of clavulanate.

Explanation: Amoxicillin–clavulanate is composed of amoxicillin and clavulanate potassium, and the standard combination is designed so that the ratio of amoxicillin to clavulanate is fixed. When using two 250-mg tablets, the patient would receive 125 mg of clavulanate instead of the intended 62.5 mg per 250-mg tablet, effectively doubling the intended dose of clavulanate.

Question 3

3. A cardiac surgeon orders cefazolin 1 g IV “on call” to the operating room for a patient scheduled for a
   heart valve replacement. The surgery is scheduled for 7:00 am the next morning. What is the rationale
   for giving the antibiotic at 6:30 am? The last dose was administered more than 8 hours ago.
   A. The cefazolin must be given 60 minutes before the procedure for legal reasons.
   B. The cefazolin must be given within 60 minutes before the first skin incision to reach therapeutic
   concentrations.
   C. The cefazolin trough level will be checked at 6:00 am, which would allow the level to come back
   before administration of the “on call” dose.
   D. The last dose was administered yesterday.

Answer 3

Correct Answer: B. The cefazolin must be given within 60 minutes before the first skin incision to reach therapeutic concentrations.

Explanation: Cefazolin is typically administered as a prophylactic antibiotic prior to surgery to prevent surgical site infections. It is essential that the antibiotic reaches therapeutic levels in the bloodstream before the incision is made. Administering it 30 minutes before surgery (at 6:30 am for a 7:00 am surgery) ensures that the drug is at effective levels when the incision occurs.

Question 4

Which of the following classes of cephalosporins have the best activity against gram-positive
organisms?
A. first-generation cephalosporins
B. second-generation cephalosporins
C. third-generation cephalosporins
D. fourth-generation cephalosporins