When is the Amoxicillin 2 g dose described for adult prophylaxis relative to the appointment?

• A. 1 hour prior to appointment
• B. 2 hours post op
• C. Immediately after appointment
• D. 4 hours before

Answer: (A)

Giving the amoxicillin dose about one hour before the dental appointment ensures protective antibiotic levels are present in the bloodstream and tissues right when the procedure may introduce bacteria into the bloodstream. Amoxicillin is absorbed quickly, and its levels peak within roughly an hour after ingestion, so timing the dose about an hour prior places effective concentrations at the moment of bacteremia. If given too early, levels may fall below protective levels by the time the procedure starts; if given after the procedure, the window to prevent bacteria from seeding vulnerable sites is missed.