A team of Scottish researchers found that taking too much paracetamol on a regular basis puts a patient at high risk of an accidental overdose.
A paper, published in the British Journal of Clinical Pharmacology, highlights the hidden risks from ‘staggered’ consumption of the over-the-counter painkiller. Experts from the University of Edinburgh and the Scottish Liver Transplantation Unit warn that although the danger is difficult to pinpoint, taking a little bit more paracetamol than you should when in pain can lead to an overdose.
One of the study authors Dr Kenneth Simpson from the University of Edinburgh comments on patients who experience these so-called ‘staggered overdoses’: ‘They haven’t taken the sort of single-moment, one-off massive overdoses taken by people who try to commit suicide, but over time the damage builds up, and the effect can be fatal’.
Often patients who have experienced these types of overdoses come to the hospital because they are in pain and not because they believe they have taken an overdose. The team are calling for quicker recognition of this clinical situation; these types of overdoses can even be more dangerous than a single overdose, classed as consuming 4 g or more in a single intake, or around eight tablets.
The problem stems from the way that doctors assess how much danger an overdose patient is in when they arrive at the hospital. This is normally done by taking a blood sample and finding out how much paracetamol is present. When the patient has taken a single overdose, this blood sample gives valuable information. The teams’ conclusions are based on a data analysis of 663 patients who had been admitted to the Royal Infirmary of Edinburgh between 1992 and 2008 with paracetamol-induced liver injury. They found that 161 had taken a staggered overdose, usually to relieve a variety of common pains such as abdominal or muscular pains, headache and toothache. This means that nearly one in four patients admitted to the hospital with paracetamol-induced liver failure had accidentally overdosed on the drug while trying to treat these common ailments.
Medical experts advise patients to take heed of the advice on paracetamol packets and not exceed the daily recommended dose. Each tablet usually contains 500 mg: adults can take 1 or 2 tablets of paracetamol every 4 to 6 hours up to 4 times a day. In other words, you shouldn’t take more than 4 g or 8 tablets in a single 24-hour period.