Plain English Summary

Not provided at time of registration

Trial website

Contact information



Primary contact

Dr Stephen Fenlon


Contact details

Queen Victoria Hospital NHS Foundation Trust
Holtye Road
East Grinstead
RH19 3QE
United Kingdom

Additional identifiers

EudraCT number number

Protocol/serial number


Study information

Scientific title

A comparison of pre-medication with oral paracetamol versus intravenous paracetamol given at time of induction for post-operative analgesia following wisdom tooth extraction


Study hypothesis

There is no clinically significant difference between the post-operative analgesic effects of paracetamol when given orally as a pre-medication one hour pre-operatively, and when given as an intravenous infusion immediately pre-operatively.

Ethics approval

Brighton East Research Ethics Committee approved as of 19th February 2008 (ref: 08/H1107/16)

Study design

Randomised, controlled, blinded trial

Primary study design


Secondary study design

Randomised controlled trial

Trial setting


Trial type


Patient information sheet

Not available in web format, please use the contact details below to request a patient information sheet


Analgesia in wisdom tooth extraction


Participants will be randomly assigned to either:
1. Oral pre-med group: two 500 milligram paracetamol capsules and 100 ml bag of normal saline for injection, or
2. IV group: two placebo lactose capsules and 100 ml (1 gram) of paracetamol for injection

The oral pre-medication will be given one hour prior to surgery and the intravenous whilst the participant is under a general anaesthetic. Duration of treatment 15 minutes for intravenous injection. Duration of follow up until discharged from hospital (max 3 - 4 hours).

Intervention type



Not Specified

Drug names


Primary outcome measures

We will compare the pain scores of patients in the two study arms one hour post-operatively. This will be done in recovery using a Visual Analogue Scale (VAS) pain scoring system.

Secondary outcome measures

We will compare the time to request of post-operative ‘rescue’ analgesia between the two study arms. Specifically, this will be measured from when the patient arrives in recovery. This point will serve as a standard ‘time zero’ (t0). The time elapsed before the patient requests additional analgesia (if at all) will act as a secondary surrogate marker of analgesic efficacy.

Overall trial start date


Overall trial end date


Reason abandoned


Participant inclusion criteria

Patients over 18 years (either sex) having a general anaesthetic for extraction of wisdom teeth of which at least one must be a lower molar tooth.

Participant type


Age group




Target number of participants


Participant exclusion criteria

1. Patients who are unable to give full consent, or who do not wish to take part in the trial
2. Patients who have a baseline Visual Analogue Scale (VAS) score of more than zero
3. Patients unable to swallow tablets
4. Patients who have taken simple analgesics that day, prior to surgery
5. Hypersensitivity or history of serious adverse reactions to paracetamol or non-steroidal anti-inflammatory drugs
6. Active liver disease
7. Renal dysfunction
8. Pregnant or breast feeding women
9. Alcohol or drug abuse
10. History of unresponsiveness to paracetamol
11. Gastric or peptic ulcer disease
12. Inflammatory bowel disease
13. Blood coagulation abnormalities

Recruitment start date


Recruitment end date



Countries of recruitment

United Kingdom

Trial participating centre

Queen Victoria Hospital NHS Foundation Trust
East Grinstead
RH19 3QE
United Kingdom

Sponsor information


Queen Victoria Hospital NHS Foundation Trust (UK)

Sponsor details

Holtye Road
East Grinstead
RH19 3DZ
United Kingdom

Sponsor type




Funder type


Funder name

National Institute for Health Research (UK) - the Research for Patient Benefit (RfPB) programme

Alternative name(s)

Funding Body Type

Funding Body Subtype


Results and Publications

Publication and dissemination plan

Not provided at time of registration

Intention to publish date

Participant level data

Not provided at time of registration

Results - basic reporting

Publication summary

1. 2012 results in

Publication citations

  1. Results

    Fenlon S, Collyer J, Giles J, Bidd H, Lees M, Nicholson J, Dulai R, Hankins M, Edelman N, Oral vs intravenous paracetamol for lower third molar extractions under general anaesthesia: is oral administration inferior?, Br J Anaesth, 2013, 110, 3, 432-437, doi: 10.1093/bja/aes387.

Editorial Notes