ADHD medication poisonings soar

Poisonings from medications prescribed for attention deficit hyperactivity disorder (ADHD) have increased fourfold in the past 10 years in Australia, according to a new study.
 
Researchers from the University of Sydney described the increase in poisonings from a range of ADHD drugs as ‘a growing public health issue’, with reported poisonings rising from 795 in 2014 to 3242 in 2023.
 
It also found that children are most likely to have an adverse exposure to ADHD medication, with 72% of accidental poisonings taking place among those aged under 15 years.
 
The research used nationwide data to examine cases of human exposures to six medications currently used to treat ADHD: atomoxetine, clonidine, dexamphetamine, guanfacine, lisdexamfetamine and methylphenidate. 
 
They also accessed dispensing data from the Pharmaceutical Benefits Scheme (PBS), finding a ‘strong correlation’ between exposures and number of prescriptions.
 
The data showed clonidine and methylphenidate are the two most common medications implicated in poisonings, each accounting for 35% of all reports, and the highest number of hospital presentations.
 
While the researchers believe the significant increase in ADHD diagnoses has played a part in the spike in poisonings, they also found the rate of clonidine poisonings are ‘disproportionately high’ compared to the number of prescriptions issued.
 
‘Clonidine poisonings are outstripping diagnosis rates,’ said Amy Thomson, the study’s lead author.
 
‘The self-reported data captures only those who phoned the poisons hotline or who presented to hospital with symptoms of poisoning,’ she said. ‘The true scale of the problem could be much more significant.’
 
When used to treat ADHD, clonidine is often prescribed as a quarter or a half dose of a tablet, potentially making it ‘tricky to administer accurately’, raising the risk of dosing errors, said Ms Thomson.
 
‘Another reason can be miscommunication within the family, typically where both parents give their child a dose of medication, not realising the other has already done it,’ she said.
 
‘Just one double dose of clonidine can put a child in hospital.’ 
 
RACGP Specific Interests Child and Young Person’s Health Chair, Dr Tim Jones, told newsGP he has also heard anecdotally of increasing reports of harm to children due to parents accidentally giving more medication than intended.
 
He also agrees with Ms Thomson’s concern of children ‘trying out’ a sibling’s medication, adding that the increase in diagnosis of ADHD is also leading to ‘more and more kids just sharing medication’.

‘That has lots of risks, but with clonidine, it has a particularly high risk due to its unpredictable effects and dosing range,’ Dr Jones said.
 
He said the ‘sensible steps’ would be for manufacturers to make clonidine available not only in a lower-dose tablet, but also in smaller quantities.
 
As a medication long used to treat adults for a variety of conditions, ranging from hypertension to post-traumatic stress disorder, the standard PBS prescription for clonidine is a 100-tablet supply.
 
‘If someone finds them who’s not usually taking them, the risk if they just swallow 10 or 20 of them is very high,’ Dr Jones said

‘The minimum kids would be taking is half to one tablet once or twice a day, so they don’t need that much each month.
 
‘Clonidine is a medicine probably GPs are more familiar with using in other conditions, but even in adults, we’ve got to be careful with doses.
 
‘Adults are quite sensitive to it, and it can’t be suddenly stopped. If you’re taking it regularly, it needs to be weaned. So, we just need to be very aware that kids are even more sensitive to dose.’
 
Chair of RACGP Specific Interests ADHD, ASD and Neurodiversity, Associate Professor John Kramer, told newsGP that the popularity of clonidine is due to it being on the PBS and ‘relatively cheap’.
 
‘It does need to be used with care, but it can also be a dramatically effective medication,’ he said.
 
As more GPs move into ADHD diagnosis and treatment, Dr Jones said the study’s findings are a reminder for GPs to be ‘very thoughtful’ and ‘remember our role as educators of families’.
 
‘We have to help families understand the safety profile of these medications, how to use them responsibly, and what the risks are if there’s a missed dose,’ he said.
 
Log in below to join the conversation.

ADHD ADHD medication attention deficit hyperactivity disorder clonidine overdose poisoning Ritalin