Scottish and Newcastle Anti-emetic Pre-treatment for Paracetamol Poisoning Study (SNAP)

Launched by UNIVERSITY OF EDINBURGH · Jan 14, 2010

Keywords

ClinConnect Summary

Paracetamol is the commonest poison seen in the United Kingdom and is present in approximately 40% of patients admitted with self harm. Current treatment involves use of the antidote acetylcysteine in patients deemed at risk of potential liver damage. This is given by intravenous infusion over a period of 20.25 hours. This regimen was designed in the 1970s and is empirical, in that a large loading dose of the antidote is administered followed by 2 decreasing concentrations. It is cumbersome to calculate and dilute within the ward and therefore subject to error in preparation. The initial in...

Gender

ALL

Eligibility criteria

• Inclusion Criteria:
• • Any patient admitted to hospital within 36 hours of a single acute paracetamol overdose; AND
• • Requires treatment with acetylcysteine.
• These patients will include:
• • Patients with no risk factors and timed paracetamol concentrations above the 200-line on the UK paracetamol overdose treatment nomogram.
• • Patients with at least 1 risk factor and timed paracetamol concentrations above the 100-line on the UK paracetamol overdose treatment nomogram
• • Patients presenting \>8 hours, and at risk of liver damage based on history of dose ingested (BNF) that need immediate treatment
• Risk factors are defined as follows:
• • Nutritional deficiency, malnourished and/or debilitating disease: acute or chronic starvation, eating disorders, cachexia, malabsorption syndromes, AIDS, cystic fibrosis, hepatitis C, chronic alcoholism.
• • Enzyme induction: use of drugs with this property (carbamazepine, rifampicin, barbiturates, phenytoin, rifabutin, efavirenz, nevirapine, St John's Wort; regular consumption of ethanol above advised amounts.
• Exclusion Criteria:
• Patients:
• • \< 16 years old
• • Detained under the Mental Health Act
• • With known permanent cognitive impairment
• • With a life-threatening illness
• • Who are known to be pregnant
• • Who have previously participated in the study
• • Unreliable history of paracetamol overdose
• • Vomiting and requiring treatment antiemetic prior to randomisation
• • Presenting after 36 hours of a single acute paracetamol overdose
• • Presenting after taking a staggered paracetamol overdose (defined as when the overdose of paracetamol is taken over a period of more than 2 hours)
• • Who take anticoagulants (e.g. warfarin) therapeutically or have taken an overdose of anticoagulants
• • Who, in the opinion of the responsible clinician/nurse, are unlikely to complete the full course of acetylcysteine e.g. expressing wish to self-discharge
• • Who in the opinion of the responsible clinician/nurse are unable to complete the initial questionnaire either themselves or with nurse assistance.
• • Who have a history of hypersensitivity to 5HT3 antagonists
• • Non-English speaking patients. (Trial information material will only be produced in English in view of the known and stable demographic of the Edinburgh and Newcastle self harm population)