The nurse is caring for a patient who is receiving an intravenous antibiotic. The nurse notes that the provider has ordered serum drug peak and trough levels. The nurse understands that these tests are necessary for which type of drugs?

Correct Answer: D

Rationale: Medications with a narrow therapeutic index have a limited range between the therapeutic dose and a toxic dose. It is important to monitor these medications closely by evaluating regular serum peak and trough levels. Drugs with a narrow spectrum (Choice B) are antibiotics that target only a limited group of bacteria, not related to the need for peak and trough monitoring. Drugs with a broad spectrum (Choice A) cover a wide range of bacteria, but this characteristic does not determine the need for peak and trough monitoring. Drugs with a broad therapeutic index (Choice C) have a wide safety margin between therapeutic and toxic doses, so they typically do not require peak and trough level monitoring.

Correct Answer: C

Rationale: The nurse should question the order for Erythromycin 300 mg IM QID. Erythromycin and other macrolides should not be given intramuscularly because they cause painful tissue irritation. Options A and B are correct routes for Azithromycin, either intravenously or orally. Option D is a correct route for Erythromycin, which is orally.

Correct Answer: B

Rationale: When vancomycin is infused too rapidly, "red man" syndrome may occur; the rate should be 10 mg/min to prevent this. This is a toxic reaction, not an allergic one, so epinephrine is not indicated. Stevens-Johnson syndrome is characterized by a rash and fever. Red man syndrome is not related to renal function.

Correct Answer: C

Rationale: When a patient receiving gentamicin (Garamycin) reports experiencing ringing in the ears, it is crucial to consider the possibility of ototoxicity. Ototoxicity is a known adverse effect of aminoglycosides. The appropriate action for the nurse in this situation is to contact the provider to discuss obtaining a serum drug level. This is important to assess the drug concentration in the patient's blood, which can help determine if the ringing in the ears is related to the medication. Decreasing the dose or changing the dosing frequency without assessing the serum drug level may not address the underlying issue and could potentially lead to suboptimal treatment. Ordering a hearing test may be necessary at a later stage if the serum drug level indicates a concern. Therefore, option C, obtaining a serum drug level, is the most appropriate action to take in this scenario.

Correct Answer: A

Rationale: The correct answer is A: '5 mL PO BID.' To calculate the child's daily dose requirement, you multiply the child's weight (10 kg) by the prescribed dosage per kg, which is 8 mg for TMP and 40 mg for SMX. This results in a total daily requirement of 80 mg of TMP and 400 mg of SMX. To divide this into two doses, each dose should contain half of the total daily requirement, which is 40 mg TMP and 200 mg SMX. Since the liquid preparation contains 40 mg of TMP and 200 mg of SMX per 5 mL, the correct dose per administration is 5 mL. Therefore, 5 mL PO BID is the correct order. Choice B, '5 mL PO daily,' is incorrect as the total daily dose needs to be divided into two doses. Choices C and D, '10 mL PO BID' and '10 mL PO daily,' respectively, are incorrect as they do not align with the calculated dosage requirements based on the child's weight and the prescribed dosage per kg.