9 April 2018

Slow-release opioids under the spotlight

Clinical Drugs Pain Patients

Too many patients are being released from hospital on slow-acting opioids for acute pain, in a practice that isn’t evidence-based and could be fatal, pain specialists warn. 

After a number of fatalities and reported cases of dangerous respiratory depression, the Australian and New Zealand College of Anaesthetists issued a warning to dozens of medical colleges about the slow-release formulations. 

“The concern is that there is fairly widespread use of a lot of slow-release formulations, even including fentanyl patches for acute pain relief,” Dr Michael Vagg, from ANZCA’s Faculty of Pain Medicine, said. 

It had become too common for relatively fit patients to visit hospital for day surgery or an emergency visit and be released on potent and long-acting opioids, despite warnings from overseas not to, the college noted.

This was associated with significant problems, such as dose accumulation. 

“In acute pain you need to be able to adapt your dosing to what the pain is doing, and you need to be able to back it off when the pain settles,” he said. 

“You need to be able to increase it safely if the patient needs more – and trying to do that when you’ve got something that will continue to release into the blood stream for eight to 12 hours can become quite dangerous.” 

The risks were especially high among opioid naïve patients, as well as the obese, those with sleep apnoea and patients taking sedatives such as benzodiazepines and some antihistamines, antidepressants and antipsychotics. 

But many clinicians might not have even realised prescribing these opioids for acute pain was off-label and not recommended, the experts said. 

As a result, they called on the 34 medical colleges and associations here and in New Zealand to sound the alarm. 

With the opioid epidemic gripping America and rearing its head here, medical groups are proactively trying to rein-in risky opioid prescribing. 

“We’ve got a problem in our country with illicit opioid use and even chronic opioid use, and sadly there is an emerging body of evidence that suggests that can be traced back to what was thought to be a clinically appropriate prescription of a few days of long-acting opioids,” AMA President Dr Michael Gannon said. 

While he said it was “very important that doctors make individual decisions about individual patients in terms of what and how to prescribe”, Dr Gannon said the organisation supported the college’s move to establish guidelines to improve safer prescribing around opioids. 

The research now indicates that patients are more likely to be long-term opioid users if they were given slow-release opioids after surgery, and if they were given more than necessary to take home. 

Regularly administered slow-released opioids were just as dangerous as intravenous background infusion when it came to patient-controlled analgesia, the college noted. However, the warning signs were often overlooked in patients, particularly opioid naïve patients, when respiratory rates were in the “normal range”. 

As part of it’s campaign, the college is also calling on specialists to improve opioid management when patients are discharged from hospital. 

“The way day-surgery units and specialists communicate with GPs when it comes to the timely arrival of discharge summaries and explaining changes to patient medications are all major issues that aren’t new,” Dr Gannon said. “But they need to do better.” 

Patients should not be coming home from hospital on long-acting opioids that they didn’t go into hospital on, Dr Vagg said.

 “If they are, then they should be weaned and stopped at the first possible opportunity. 

“The actual technicalities of weaning patients off the medications is not especially difficult,” he said, adding that if the pain was reasonably well managed after the operation then GPs could advise patients to reduce their dose by 30% to 50% every day or two. 

He said the real challenge was to explain to patients what was happening and why, “and that you’re not just going to abandon them if they get increased pain – there is a plan for that too”.