Skip main navigation

£199.99 £139.99 for one year of Unlimited learning. Offer ends on 28 February 2023 at 23:59 (UTC). T&Cs apply

Find out more


In this article we will discuss paracetamol roles in perioperative analgesia.


There is very little downside to prescribing oral paracetamol preoperatively. It is a cheap and effective opioid-sparing agent which is well tolerated.


Analgesic and antipyretic.


  • PO tablet or liquid formulations of varying strengths
  • IV Clear colourless 10mg/ml solution
  • PR suppository


  • Analgesia
  • Anit-pyretic
  • Anti-inflammatory

The exact mechanism of action is unclear but it acts on multiple receptors including COX1/2 (cyclooxygenase), 5HT3 (serotonin) and CB1 (cannabinoid) receptors.


  • Analgesic and anaesthetic sparing effect
  • Decreased postoperative nausea and vomiting
  • Improved intestinal motility
  • Enhanced recovery

Proven benefit in bowel surgery in terms of return of normal function and lower postoperative pain scores.


15 mg/kg every 6 hours.

The plasma level achieved at recommended levels is relatively low. Although, toxicity is rare patients should be monitored for clinical signs and symptoms.


  • PO: 45 minutes to peak plasma level with peak analgesic time 1-2 hours after.
  • IV: 20 minutes to peak plasma level with peak analgesic time 1-2 hours after.


  • Bioavailablity 63-89% (Oral), 100% (Intravenous)
  • Elimination half-life ~ 2hours
  • Plasma protein binding ~ 70-80%
  • Metabolized by the liver
  • Excreted in the urine

Rectal administration has unpredictable bioavailability and low patient acceptability. This route can be considered if alternatives are not feasible.


  • Liver Failure
This article is from the free online

Introduction to Using Total Intravenous Anaesthesia (TIVA)

Created by
FutureLearn - Learning For Life

Our purpose is to transform access to education.

We offer a diverse selection of courses from leading universities and cultural institutions from around the world. These are delivered one step at a time, and are accessible on mobile, tablet and desktop, so you can fit learning around your life.

We believe learning should be an enjoyable, social experience, so our courses offer the opportunity to discuss what you’re learning with others as you go, helping you make fresh discoveries and form new ideas.
You can unlock new opportunities with unlimited access to hundreds of online short courses for a year by subscribing to our Unlimited package. Build your knowledge with top universities and organisations.

Learn more about how FutureLearn is transforming access to education