Medications · MED-1.5
A patient is starting a course of metronidazole. According to the label, what must the patient avoid during therapy and for at least three days afterward?
- AAlcohol
- BMilk products
- CCitrus juice
- DHigh‑fiber meals
The answer is A
Why it is right. Metronidazole’s label warns of a disulfiram‑like reaction when alcohol is consumed, requiring avoidance of alcohol and propylene glycol‑containing products during therapy and for at least three days afterward.
Why each of the others was tempting
BAlcohol‑like interaction with dairy
Would be right if: The drug had a known calcium interaction.
What rules it out: Metronidazole’s warning specifically involves alcohol, not dairy.
CGrapefruit interaction
Would be right if: The medication were a CYP3A4 substrate.
What rules it out: No grapefruit interaction is listed for metronidazole.
DFiber affects absorption
Would be right if: The drug’s label warned about fiber.
What rules it out: Metronidazole’s label does not mention fiber.
The key against the next best. Only alcohol is explicitly contraindicated with metronidazole due to the disulfiram‑like reaction.
