Introduction of naloxone combo may have encouraged oxycodone use

An increased uptake of the combination drug likely 'related to its effects on constipation'

The introduction of subsidised oxycodone/naloxone controlled-release (CR) tablets in 2011 may have driven up overall use of oxycodone CR, Australian research suggests. 

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The study of PBS data showed the quarterly growth rate of oxycodone CR tablets was 13.6 per 1000 patients between 2006 and 2011.

However, between 2011 and 2016, it  rose to 22.0 per 1000 patients.

The increase was entirely driven by scripts for 5mg oxycodone/naloxone CR tablets, but only partially compensated by a decrease in low-dose single-ingredient oxycodone scripts.

Scripts for other strong opioids were also unaffected.

Study author Dr Andrea Schaffer (PhD), an epidemiologist at UNSW Sydney, said the lower risk of side effects was potentially encouraging broader use of oxycodone CR.   

“That’s what we think is happening. There might be this new population of patients who normally wouldn’t start on oxycodone,” she said.

Writing in Pharmacoepidemiology and Drug Safety, Dr Schaffer and colleagues said Australia was unusual because oxycodone/naloxone CR tablets were marketed heavily as a treatment for opioid-induced constipation.

In other countries, they tended to be marketed based on their anti-misuse properties.

“Given the observed decline in use of the tamper‐resistant single‐ingredient oxycodone CR, it is likely that much of the increased uptake of oxycodone/naloxone CR is related to its effects on opioid‐induced constipation,” they wrote.

The number of patients starting on the combination drug showed “a real or perceived need for opioids that reduce the risk of constipation”, they wrote.

But they stressed the proven benefits were mostly for treatment of pre-existing opioid-induced constipation, with only a small preventive benefit.

More information: Pharmacoepidemiology and Drug Safety 2018