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Non-Opioid Analgesic / Antipyretic (IV) Pregnancy: §4.6, verbatim: 'A large amount of data on pregnant women indicate neither malformative, nor feto/neonatal toxicity. Epidemiological studies on neurodevelopment in children exposed to paracetamol in utero show inconclusive results. If clinically needed, paracetamol can be used during pregnancy however it should be used at the lowest effective dose for the shortest possible time and at the lowest possible frequency.' Lactation, verbatim: 'After oral administration, paracetamol is excreted into breast milk in small quantities. No undesirable effects on nursing infants have been reported. Consequently, Paracetamol may be used in breast-feeding women.'

Paracetamol IV (Burns Multimodal Analgesia)

Brand names: Perfalgan

Intravenous paracetamol is a non-opioid analgesic and antipyretic used as the foundation of multimodal burns analgesia, given when the oral route is unavailable or rapid, reliable plasma levels are needed.

Adult dose

Dose: 1 g (100 ml of the 10 mg/ml solution) per administration for patients weighing more than 50 kg. For patients weighing more than 33 kg and up to 50 kg the dose is 15 mg/kg per administration (1.5 ml/kg), maximum 75 ml per administration. §4.2, verbatim: 'The dose to be administered and the bottle size to be used depend exclusively on the patient`s weight ... The volume to be administered must not exceed the determined dose.'
Route: Intravenous infusion. §4.2, verbatim: 'Intravenous use. The paracetamol solution is administered as a 15-minute intravenous infusion.' Presentation is restricted by weight, verbatim: 'The 100 ml bottle is restricted to adults, adolescents and children weighing more than 33 kg.'
Frequency: At least 4 hours between administrations and no more than 4 doses in 24 hours. §4.2, verbatim: 'The minimum interval between each administration must be at least 4 hours. The minimum interval between each administration in patients with severe renal insufficiency must be at least 6 hours. No more than 4 doses to be given in 24 hours.'
Max: Maximum daily dose 4 g for patients over 50 kg with no additional risk factors for hepatotoxicity, and 3 g for patients over 50 kg with additional risk factors for hepatotoxicity; 3 g for patients over 33 kg and up to 50 kg. §4.2, verbatim: 'Adults with hepatocellular insufficiency, chronic alcoholism, chronic malnutrition (low reserves of hepatic glutathione), dehydration: The maximum daily dose must not exceed 3000 mg.' No more than 4 doses in 24 hours.
The §4.2 weight table splits adults by hepatotoxicity risk, verbatim: '> 50 kg with additional risk factors for hepatotoxicity — 1 g — 100 ml — maximum daily dose 3 g' and '> 50 kg and no additional risk factors for hepatotoxicity — 1 g — 100 ml — maximum daily dose 4 g'. The daily maximum assumes no other paracetamol source, verbatim: 'The maximum daily dose as presented in the table above is for patients that are not receiving other paracetamol containing products and should be adjusted accordingly taking such products into account' and §4.4: 'In order to avoid the risk of overdose, check that other medicines administered do not contain either paracetamol or propacetamol.' ⚠️ mg/ml CONFUSION IS A LABELLED FATAL-ERROR RISK — §4.2, verbatim: 'Take care when prescribing and administering Paracetamol to avoid dosing errors due to confusion between milligram (mg) and millilitre (ml), which could result in accidental overdose and death ... When writing prescriptions, include both the total dose in mg and the total dose in volume.' Step down off the IV route as soon as possible — §4.4, verbatim: 'Prolonged or frequent use is discouraged. It is recommended that a suitable analgesic oral treatment will be used as soon as this route of administration is possible.' and 'Doses higher than those recommended entail the risk of very serious liver damage.'

Paediatric dose

Route: Intravenous infusion over 15 minutes. §4.2, verbatim, for patients weighing 10 kg or less: 'The volume to be administered should be withdrawn from the ampoule and diluted in a sodium chloride 9 mg/ml (0.9%) solution or glucose 50 mg/ml (5%) solution or a combination of both solutions up to one tenth (one volume Paracetamol into nine volumes diluent) and administered over 15 minutes' and 'A 5 or 10 ml syringe should be used to measure the dose as appropriate for the weight of the child and the desired volume. However, this should never exceed 7.5 ml per dose.'
Frequency: At least 4 hours between administrations (at least 6 hours in severe renal insufficiency); no more than 4 doses in 24 hours
Max: Maximum daily dose 2 g for weight over 10 kg and up to 33 kg, and 3 g for weight over 33 kg and up to 50 kg. No more than 4 doses in 24 hours.
Concentration: 10 mg/ml
⚠️ dosePerKg IS NULL ON PURPOSE — THE PER-DOSE FIGURE IS WEIGHT-BANDED AND CHANGES. §4.2 dosing table, verbatim: '≤ 10 kg — 7.5 mg/kg per administration — 0.75 ml/kg — maximum volume 7.5 ml — maximum daily dose 30 mg/kg'; '> 10 kg to ≤ 33 kg — 15 mg/kg per administration — 1.5 ml/kg — maximum volume 49.5 ml — maximum daily dose 60 mg/kg not exceeding 2 g'; '> 33 kg to ≤ 50 kg — 15 mg/kg per administration — 1.5 ml/kg — maximum volume 75 ml — maximum daily dose 60 mg/kg not exceeding 3 g'. A single per-kilogram number would DOUBLE the dose for an infant weighing 10 kg or less, so no weight-calculator figure is applied and the band must be read off the table above. The 24-hour ceiling below 10 kg is expressed only per kilogram (30 mg/kg/day) with no absolute gram figure, so it is not in maxDose. Presentation is restricted by weight, verbatim: 'The 50 ml bottle is restricted to toddlers and children weighing more than 10 kg and up to 33 kg. The 10 ml ampoule is restricted to term newborn infants, infants and toddlers weighing up to 10 kg.' Preterm infants, verbatim: 'No safety and efficacy data are available for premature newborn infants.' concentration is 10 mg/ml, the strength named in the product title and repeated in the §4.2 table heading 'Maximum volume of Paracetamol (10 mg/ml) per administration'. Verify against a children's formulary.

Dose adjustments

Renal

§4.2, verbatim: 'Severe renal insufficiency: It is recommended, when giving paracetamol to patients with severe renal impairment (creatinine clearance ≤ 30 ml/min), to reduce the dose and increase the minimum interval between each administration to 6 hours.' §4.4 lists severe renal insufficiency (creatinine clearance ≤ 30 ml/min) among the cautions.

Hepatic

Severe hepatocellular insufficiency is a contraindication (§4.3). §4.2, verbatim: 'Adults with hepatocellular insufficiency, chronic alcoholism, chronic malnutrition (low reserves of hepatic glutathione), dehydration: The maximum daily dose must not exceed 3000 mg.' The §4.2 table likewise caps patients over 50 kg with additional risk factors for hepatotoxicity at a 3 g daily maximum rather than 4 g.

Dose independently re-sourced from UK Summary of Product Characteristics (SPC) via the eMC — clinician-reviewed. Always confirm against the product SmPC and your local formulary before prescribing.

Contraindications

  • Hypersensitivity to paracetamol, to propacetamol hydrochloride (the prodrug of paracetamol), or to any of the excipients (§4.3)
  • Cases of severe hepatocellular insufficiency (§4.3)

Side effects

  • Increased levels of hepatic transaminases — rare (§4.8)
  • Hypotension — rare; flushing and tachycardia — isolated cases (§4.8)
  • Malaise — rare (§4.8)
  • High anion gap metabolic acidosis due to pyroglutamic acidosis — reported in severe illness such as severe renal impairment and sepsis, in malnutrition or other glutathione deficiency such as chronic alcoholism, after prolonged therapeutic dosing or with concomitant flucloxacillin (§4.4, §4.8)
  • Thrombocytopenia, leucopenia, neutropenia — very rare (§4.8)
  • Hypersensitivity reactions ranging from simple skin rash or urticaria to anaphylactic shock, requiring discontinuation — very rare (§4.8)
  • Serious skin reactions — very rare (§4.8)
  • Pruritus and erythema — isolated cases (§4.8)
  • Injection site pain and burning sensation — frequent in clinical trials (§4.8)
  • Haemolytic anaemia in genetically caused G-6-PD deficiency (favism) (§4.4)
  • Very serious liver damage with doses higher than recommended — fulminant hepatitis, hepatic failure, cholestatic hepatitis, cytolytic hepatitis, usually first seen after two days with a peak at 4–6 days (§4.4)

Monitoring

  • Check every other medicine given for paracetamol or propacetamol content before each dose, and adjust the daily maximum accordingly (§4.2, §4.4)
  • Prescribe and check both the total dose in mg AND the total volume in ml at every administration — mg/ml confusion is a labelled cause of fatal overdose (§4.2, §4.4)
  • Acid-base status where high anion gap metabolic acidosis is suspected — §4.4, verbatim: 'If HAGMA due to pyroglutamic acidosis is suspected, prompt discontinuation of paracetamol and close monitoring is recommended. The measurement of urinary 5-oxoproline may be useful to identify pyroglutamic acidosis as underlying cause of HAGMA in patients with multiple risk factors.' Risk rises with concomitant flucloxacillin, sepsis, severe renal impairment and malnutrition
  • Signs of liver damage after any suspected excess dose — clinical signs usually appear after two days and peak at 4–6 days; give the antidote as soon as possible (§4.4)
  • INR where a patient is on an oral anticoagulant — §4.5: paracetamol 4000 mg per day for at least 4 days with oral anticoagulants may lead to variations in INR values
  • Watch the container closely at the end of the infusion to avoid air embolism, particularly by a central route (§4.2)
  • Review daily whether the oral route can be used instead — prolonged or frequent IV use is discouraged (§4.4)

Clinical monograph

How it works

It produces central analgesic and antipyretic effects through poorly defined central mechanisms including modulation of prostaglandin pathways; the intravenous route bypasses variable gastrointestinal absorption.

Prescribing in practice

  • Dose by body weight and reduce in low-weight adults, hepatic impairment, malnutrition or sepsis because of the risk of hepatotoxicity, and account for all paracetamol sources to avoid inadvertent overdose; intravenous dosing errors are a recognised hazard.
  • It is opioid-sparing and reduces procedural and background opioid requirements when used as scheduled baseline analgesia.
  • Confirm there is no other paracetamol-containing medication being given concurrently before prescribing the intravenous form.

Monitoring

Monitor analgesic effect and cumulative paracetamol intake from all routes, with attention to hepatic risk factors in catabolic burns patients.

Counselling the patient

  • This is a regular non-opioid painkiller that lowers the need for stronger drugs.
  • Team: account for all paracetamol sources and reduce the dose in low body weight or liver risk.
  • Report any other paracetamol-containing products you may have taken.

Evidence & guidelines

Paracetamol as the basis of multimodal, opioid-sparing analgesia is supported by perioperative and burns analgesia guidance.

Reference: British Burns Association Analgesia Guidelines 2018; MHRA Drug Safety Update 2021 (flucloxacillin + paracetamol); NICE NG24 (Burns); Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. The structured dose values shown have been reviewed by a clinician. Monograph status: clinician-reviewed (2026-07-04).

Related

Curated clinical cross-links plus same-class fallbacks.

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