What is the dosing and route for ertapenem?

• A. 2 g every 24 hours IM
• B. 1 g every 24 hours IV only
• C. 500 mg every 12 hours IV
• D. 1 g every 24 hours IV/IO/IM

Answer: (D)

Ertapenem is given as a single daily dose because its pharmacokinetic profile allows holding a sustained effective concentration with one dose each day. The standard dose is 1 gram, administered once every 24 hours, and it can be given by intravenous or intramuscular routes. In settings where IV access is not immediately available, intraosseous administration can be used as an alternative to ensure delivery. This combination of 1 g every 24 hours and the option for IV, IM, or IO routes best fits how ertapenem is used clinically.

The other dosing patterns aren’t correct because they either involve the wrong amount (2 g or 500 mg) or the wrong frequency (every 12 hours) or restrict the route unnecessarily to IV only.