In adult nausea/vomiting, which of the following is the correct Zofran dose and permitted routes?

• A. Zofran 4 mg IV/IO/PO/IM
• B. Zofran 8 mg IV/IO/PO/IM
• C. Zofran 2 mg IV/IO/PO/IM
• D. Zofran 4 mg IM only

Answer: (A)

This question tests the standard adult dosing and the routes permitted for ondansetron (Zofran) in nausea and vomiting. A single 4 mg dose is the commonly used amount, and it can be given by multiple routes depending on the clinical situation: IV or IO for rapid effect, or PO (tablet or dissolving tablet) when the patient can take it, and IM if IV/IO access isn’t available or feasible. Using 8 mg isn’t necessary here and raises the risk of side effects without additional benefit, while 2 mg would be too low for effective control in adults. Restricting to IM only would unnecessarily limit options when IV, IO, or PO routes are appropriate.