Image: Intranasal naloxone is easier to administer than intramuscular naloxone
Harm reduction researchers are calling for greater effort into establishing optimal dosing for opioid overdose reversal drug, naloxone, after a recent study showed intranasal delivery to be effective in preventing overdose deaths.
The study, published in the JAMA Network Open, found that people given a dose of intramuscular naloxone were more likely to recover from an opioid overdose within ten minutes than those who were given a dose of intranasal naloxone.
Professor Paul Dietze, Burnet Program Director, Behaviours and Health Risks said the study showed that overall, intranasal naloxone is effective for reversing opioid overdose and that it was now imperative to establish the optimal dosage.
“At that particular dose of intranasal naloxone, which is less than the dose which is currently out in the market in Australia, the effectiveness wasn’t quite as high as intramuscular naloxone,” Professor Dietze said.
Professor Dietze pointed out that the study, conducted over five years at the Uniting Medically Supervised Injecting Centre (MSIC) in Sydney, only sought to compare the effectiveness of intranasal and intramuscular administration and not optimal dosage.
“We need to work out the best dosing in relation to naloxone, not just intranasal but intramuscular naloxone, that’s an international priority,” Professor Dietze said.
Professor Dietze welcomed the recent listing of intranasal naloxone on Australia’s Pharmaceutical Benefits Scheme (PBS) – at a higher dosage than in the study – and said it was important to research its effectiveness at increased doses.
“Putting easy-to-use naloxone in the hands of the people who come across people who might have had an overdose really does enable a quick response,” he said.
Novel study design eliminates bias
The double-blind, double-dummy study saw 197 people who overdosed in the Sydney MSIC given both a dose of intranasal and intramuscular naloxone, one of which was a placebo. MSIC staff did not know which dose was the placebo to eliminate bias.
The study found 76 per cent of people who received intranasal naloxone recovered within 10 minutes, compared to 92 per cent of people who received an initial dose of intramuscular naloxone.
Participants who did not initially recover were given an additional ‘top-up’ or rescue dose and made a full recovery.