Paracetamol overdose treatment ‘costing millions’

Edinburgh University researchers analysed the effect of the change in policy. Picture: Jane Barlow

APPLYING new, stricter guidelines on the treatment of paracetamol overdoses is costing the NHS millions of pounds a year, a Scottish study has claimed.

Rules on which patients should be given an antidote after a paracetamol overdose were changed 18 months ago, meaning even those with relatively low levels of the drug in their system are now given treatment.

But an assessment by Edinburgh University found that the change had increased costs massively and could be putting more patients at risk of suffering side-effects.

Threshold reduced

The Medicines and Healthcare products Regulatory Agency (MHRA) revised its guidance on treatment with the antidote acetlycysteine, which is given by intravenous drip, following the death of a young girl from a paracetamol overdose.

Under the previous guidelines, everybody with a paracetamol blood concentration above 200 milligrams per litre (mg/L) would be treated with the antidote.

Doctors used to conduct a risk assessment on patients with between 100mg/L and 200mg/L and treat only when they thought it was necessary.

But after the changes, the risk assessment was abandoned and now doctors treat everybody with a paracetamol blood concentration above 100mg/L.

Most other countries, including Canada, the United States and Australia, use 150mg/L as their threshold for treatment with acetlycysteine.

By lowering the treatment threshold to include patients with relatively low paracetamol levels, the MHRA predicted it would save one additional life around every two years.

Numbers up almost 50%

The Edinburgh researchers set out to assess the impact of the MHRA’s decision to revise the guidelines.

They found that the number of patients receiving hospital treatment for paracetamol poisoning in the UK each year has risen by almost 50 per cent since the guidelines were updated.

According to the study, more than 31,000 extra patients would need to be treated to achieve the target of saving an additional life every two years at an approximate cost of £17.4 million to the NHS.

The researchers, writing in the British Journal of Clinical Pharmacology, said that treatment could also be placing patients at unnecessary risk of unwanted side effects from the antidote, such as severe allergic reactions.

The team estimated the impact of the revised guidelines by looking at the numbers of patients treated for paracetamol poisoning at large hospitals in Edinburgh, London and Newcastle upon Tyne.

By applying their findings to the rest of the UK, they estimated that the number of patients receiving hospital treatment for paracetamol poisoning increased from around 33,000 to 49,000 a year after the changes were introduced.

Professor Nick Bateman, of Edinburgh University’s British Heart Foundation Centre for Cardiovascular Science, said: “Changes to the treatment guidelines for paracetamol overdoses are increasing the pressure on hard-pressed emergency departments and hospitals.

“A full review of present UK approaches to managing this common poisoning is required.”

Overdose common, deaths rare

Paracetamol is the most common cause of overdose in the UK but deaths are rare – between 150 and 250 people a year.

Some people overdose mistakenly due to confusion over which over-the-counter medicines contain paracetamol.

Dr June Raine, director of vigilance and risk management of medicines at the MHRA, said: “Paracetamol poisoning can be life threatening if people who have taken an overdose are not treated quickly with the antidote by medical staff.

“Based on an independent expert review, we have simplified the guidelines to improve the treatment of people who are suffering from paracetamol poisoning because we were aware that in clinical practice there were difficulties in interpreting the previous guidance.

“We are aware of at least ten people who have died since 1991 because they didn’t receive the antidote.

“The antidote is almost 100 per cent effective if administered within eight hours of overdose. We are continuing to monitor the impact of these guidelines in patients.”