A 45-year-old female is admitted to the hospital with community-acquired pneumonia. The physician orders ceftriaxone 1 g IV daily and metronidazole 500 mg IV every 8 hours. The nurse asks if these can be administered together via the same Y-site. What is the pharmacist's most appropriate recommendation?

Question: A 45-year-old female is admitted to the hospital with community-acquired pneumonia. The physician orders ceftriaxone 1 g IV daily and metronidazole 500 mg IV every 8 hours. The nurse asks if these can be administered together via the same Y-site. What is the pharmacist's most appropriate recommendation?

Answer options:

• These can be administered together safely via the same Y-site. ✅ Ceftriaxone and metronidazole should be administered separately due to incompatibility.
• Administer ceftriaxone first, flush with normal saline, then administer metronidazole.
• Metronidazole may precipitate if mixed with ceftriaxone; use separate lines.

Correct answer: Ceftriaxone and metronidazole should be administered separately due to incompatibility.

Explanation: Ceftriaxone is incompatible with many drugs, including metronidazole. Mixing them can lead to precipitation or inactivation. They must be administered separately, ideally through different intravenous lines, or by thoroughly flushing the line between administrations if a single line is unavoidable.