The drugs are being prescribed much less often, but are increasingly used for suicide.
The message that barbiturates are toxic and addictive has been heard loud and clear.
Pharmaceutical Benefits Scheme statistics show that prescriptions dropped from 50,000 to 27,000 between 2001 and 2015.
But now the main harm from their use is suicide, not unintentional overdose, and that rate has gone up.
“While the prescribing and community use of barbiturates has declined, their increased use for intentional self-harm, particularly by people with mental health problems, is worrying,” said the authors of a national data analysis published in the MJA.
Between 2000 and 2018, there were 511 barbiturate-related deaths, 1250 hospitalisations, and 993 closed-treatment episodes, according to national mortality, coroner and treatment service data.
The good news is that annual hospitalisation rates have declined notably since 2000-01, from 107 events (0.56 per 100,000 people) to 37 (0.14 per 100,000); and drug treatment episodes have dropped from 0.67 per 100,000 people to between 0.15 and 0.44. Barbiturates were the main drug of concern in just one in five of these episodes, and were hardly ever the only drug in use.
But the annual death rate increased from 13 (0.07 deaths per 100,000 population) to 51 (0.19 per 100,000), with the increase attributable to intentional self-harm deaths. Deaths from self-harm increased 11% over this period, while accidental deaths remained steady.
Nine out of 10 of the 511 barbiturate-related deaths were intentional overdoses, either among younger people with mental health problems and low-level physical disease, or older people with high levels of physical disease but low levels of mental health problems.
“Evidence of a previous suicide attempt was available in only 78 [of these] cases (15%). It would therefore appear that a large proportion of people who attempt suicide using barbiturates succeed at their first attempt, reflecting well considered suicide planning and the lethality of barbiturates,” the researchers surmised.
Two out of three hospitalisations were a result of suicide attempts, and 58% of people admitted already had a mental health diagnosis.
“It is notable that almost two?thirds of hospitalisations were linked with deliberate self?harm, confirming the continued association of barbiturates with suicide. Further, mental health diagnoses (particularly mood disorders) were recorded in nearly three in five hospitalisations … and attempted suicide was the most frequent reason for their admission,” the authors wrote.
Not all barbiturates associated with these deaths, hospitalisations and treatment episodes were prescribed. Some were bought over the internet, and others from veterinary clinics.
Restricting these drugs is a difficult border control and public health issue, the analysis acknowledged. But despite greatly reduced prescription numbers, researchers warned that clinicians still needed to be aware of the association between barbiturates and suicide.
