What is the onset of action for acetaminophen?

What is the onset of action for acetaminophen?

• A. 30-60 minutes
• B. 2-3 hours
• C. 5-6 hours
• D. Approximately 10 minutes

Answer: (D)

Onset depends on how the drug is given. For acetaminophen, the time to see analgesic effects varies with the route of administration. When taken orally, absorption from the GI tract takes time, and the analgesic effects typically begin about 30 to 60 minutes after ingestion, with peak action occurring later. If given intravenously, the drug bypasses absorption and can produce analgesia much more quickly, often within 10 to 15 minutes during or shortly after the infusion, though peak effect may be closer to an hour. Because the question doesn’t specify the route, the most commonly taught timeframe for oral acetaminophen is 30–60 minutes. The approximately 10 minutes figure would be correct only for IV administration.

Onset depends on how the drug is given. For acetaminophen, the time to see analgesic effects varies with the route of administration. When taken orally, absorption from the GI tract takes time, and the analgesic effects typically begin about 30 to 60 minutes after ingestion, with peak action occurring later. If given intravenously, the drug bypasses absorption and can produce analgesia much more quickly, often within 10 to 15 minutes during or shortly after the infusion, though peak effect may be closer to an hour.

Because the question doesn’t specify the route, the most commonly taught timeframe for oral acetaminophen is 30–60 minutes. The approximately 10 minutes figure would be correct only for IV administration.