Poisoning with paracetamol increases again
Poisoning with paracetamol is now rising again after a temporary decline, reports the Poison Information Center. Significantly increased prescription is suspected to contribute.
Paracetamol poisoning is one of the more common intoxications in the case of intentional or unintentional drug overdose. In recent years, slow release preparations (eg Alvedon 665 mg) have complicated the clinical situation in that these preparations can cause late concentration peaks. Up to 50% of all serious poisonings occur unintentionally. The paracetamol metabolites are liver toxic and with their initially relatively symptom-free interval it is a subtle and severe intoxication. It is the enzyme CYP 450 that produces NAPQI formation. Paracetamol is the most frequent cause of acute liver failure in the United States
Poisoning with paracetamol continues to increase and topping the list of drugs behind overdose issues from the health service to the Poison Information Center, GIC. The increase has not been able to stop despite several measures. It worries GIC, who suspects that the significantly increased prescription of paracetamol is contributing to the problem.
GIC now wants to investigate whether the suspicion is correct and what measures should be taken in that case.
Poisoning with acetaminophen went down in 2018
In 2019, GIC received 1,728 requests from the hospital for poisoning cases in which the person overdosed on paracetamol, according to statistics requested by the World Medicines. It is usually about adults who have deliberately taken too large a dose. As far as possible, GIC has only counted repeated questions about the same case once and excluded harmless events.
This last year’s figure for paracetamol poisonings means that a trend violation 2018 appears to have been temporary. In 2018, for the first time since 2013, the number of paracetamol poisons went down, from the peak listing of around 1,900 cases in 2017 to 1,561 cases, which the Medicines World reported at that time.
– That decline was entirely offset by the number of cases that could previously be linked to delayed-release paracetamol, for example, Alvedon 665. The withdrawal of this formulation resulted in a temporary reduction. Still, we now see that paracetamol poisoning continues to increase and be a serious problem, says Johanna Nordmark Grass, chief medical officer, and medical manager at GIC, which is a unit within the Swedish Medicines Agency.
Measures have not been sufficient
The European Commission decided to delay paracetamol with the delayed-release because experts considered that overdoses with this formulation were extra challenging to treat. The Swedish Medicines Agency withdrew the current drugs from the Swedish market in June 2018.
Three years earlier, the Swedish Medicines Agency made another restriction on trying to do something about the acetaminophen poisonings. Since then, stores are not allowed to sell paracetamol in the form of regular tablets, but only as effervescent tablets, suppositories, and solutions.
But despite the measures taken by the authority so far, the cases of poisoning continue to increase.
– It is a huge concern, not least because paracetamol used correctly is an excellent and safe painkiller. Fortunately, it is very uncommon for deaths due to paracetamol since the care usually helps people on time. But the overdoses pose high risks and require significant healthcare resources, says Johanna Nordmark Grass.
Poorly known causes
The increase continued with small interruptions throughout the 2010s, but no one knows for sure what it is due to. Many people have pointed to sales in the grocery trade, as a probable cause. However, a pilot study conducted by the Poison Information Center last year suggests that at least that is not the whole truth.
Johanna Nordmark Grass and her colleagues did the survey to get a picture of the role prescription and non-prescription sales play for the poisonings. The background is that prescription sales are increasing significantly. However, the prescription-free sales of paracetamol in Sweden are stable at 40-45 million defined daily doses, DDD, per year since the turn of the millennium.
In 2017, 128 million DDD paracetamol was sold by prescription, which corresponds to 77 percent of total sales. 1.2 million people aged 15-85 received paracetamol on a prescription that year, which is usually cheaper for the patient than buying a prescription.
The pilot study, presented by the researchers at a European toxicology congress last year, included 216 cases of acetaminophen poisoning that occurred in 2018. GIC then asked the emergency hospitals to find out if people who overdosed had used prescription or non-prescription paracetamol.
Prescription drugs predominate
The results showed that prescription drugs accounted for 52 percent of the acetaminophen poisonings studied, and non-prescription drugs accounted for 20 percent. In other cases, it was not possible to determine which category of paracetamol the person had taken.
When it came to the 31 most serious cases, prescription drugs dominated even more. The researchers conclude with caution that the increasing availability of relatively cheap prescription paracetamol in large packages (often cans of 100 tablets) may be one reason why poisoning continues to increase.
– If many people have 100 jars at home in the medicine cabinet, perhaps accessible to others in the family as well, this could increase the risk of impulse actions where they overdose. It’s all about accessibility, says Johanna Nordmark Grass.
However, she points out that the study was too small for safe conclusions to be drawn. To obtain a basis for possible further preventive measures, the researchers want to do more extensive research.
– We hope to get started on this work this year.
What measures may be needed if a larger study confirms the pilot study’s results cannot yet be said.
– The problem probably needs to be tackled in several ways to limit the availability of prescription paracetamol. Practical constraints that reduce accessibility and various efforts to increase prescribers’ awareness of the problem can be envisaged.