The duration of action of a single IV dose of midazolam is approximately:

• A. 4-6 hours
• B. 1-2 hours
• C. 6-8 hours
• D. 10-12 hours

Answer: (B)

Midazolam is a short-acting benzodiazepine. After an IV dose, it acts quickly but wears off relatively fast because it rapidly redistributes from the brain to other tissues and is quickly metabolized by the liver. For a single IV dose in an adult with normal organ function, the clinically meaningful duration of action is about 1–2 hours. Larger doses, continuous infusions, or factors like age and hepatic impairment can prolong effects, but the typical single-dose duration is in the 1–2 hour range.