Paracetamol (IV)

How it works

Paracetamol produces analgesia and antipyresis through centrally mediated mechanisms, including effects on prostaglandin pathways and descending modulation, with minimal peripheral anti-inflammatory action.

Prescribing in practice

• Dose by body weight and reduce the dose in low body weight, malnutrition, hepatic impairment, chronic alcohol use or dehydration to avoid hepatotoxicity, and guard against accidental overdose by accounting for all paracetamol-containing products.
• Administer as a controlled infusion and double-check weight-based dosing, as intravenous administration bypasses first-pass metabolism and errors carry greater risk.
• It is opioid-sparing and combines well with NSAIDs and regional techniques as part of multimodal analgesia.

Monitoring

Routine monitoring is not required at therapeutic doses, but check liver function and consider toxicology if overdose or cumulative excess is suspected.

Counselling the patient

• This is a paracetamol drip given into a vein to help control pain and reduce reliance on stronger painkillers.
• Do not take additional paracetamol from other sources without telling staff.

Evidence & guidelines

Intravenous paracetamol is widely used and recommended as a foundation of opioid-sparing multimodal perioperative analgesia.