#10 Likelihood of chronic opioid use after first prescription

Opioid addiction has been increasingly recognised as a public health crisis:

  • Deaths from prescription painkillers have now surpassed the deaths from heroin.
  • Opioid use disorder has risen 500% from 2010 to 2016 in the USA
  • For the first time in history, the Surgeon General sent a letter to every single doctor in America. That’s over 2 million doctors! And the letter was a summary of the recommendations on opioid prescribing from the CDC. This clearly points to the importance of this issue. 

The issue is that opiates can be a very good drug. They can be a life saver in terms of pain management and they can be used in patients with kidney disease or peptic ulcer disease when other pain killers, like NSAIDs, can’t.

The scary thing about them though, is that some people become dependant.  I always have this strong fear in the back of my mind whenever I hand over an opioid script like ”am I going to ruin this patients life forever?”

This week we look into a study that asks the question: “when handing a patient a script for opioids for the first time, what is the chance that they will become a chronic user?” It also asks: ” Is there something that a doctor can do when giving a patient their first opioid prescription to reduce the risk of them becoming a chronic user?”

 

 

Methods

The state of Oregon in the USA has whats called a “Prescription Drug Monitoring Program” where they can track and monitor all prescriptions for controlled substances. Firstly, this is brilliant, because clinicians can use this data to see if a patient is drug seeking. In Australia we rely on doctors to report to a doctors shopper line, but a lot of drug seekers fall through the cracks with this system. The other reason why this monitoring program is amazing, is that it creates an unbelievable amount of great data on opioid use. The authors of this study used this data in a really genius way.

They looked at every patient that was prescribed an opiate between the years of 2012 and 2013 who were otherwise opiate naive. They classified someone as being opiate naive if they had not filled a script for opiates for 12 months prior to this first script being filled. There were 536,767 of these patients who were prescribed an opiate for the first time. And this was all outpatient prescriptions, so it didn’t include opiates dispensed in the hospital.

They then checked how many of these became chronic users. They defined that as someone who filled 6 or more scripts for opioids over the subsequent 12 month period. They had good evidence to back this up as a good marker of chronic use.

The opioids they included where analgesics, antitussives and migraine medications. They had to exclude tramadol and buprenorphine-naloxone combinations because they were not included in the prescription drug monitoring program during 2012 and 2013.

Exclusions

  • They wanted to exclude people who were prescribed opiates with the intention of being a long term prescription, like those with cancer pain or other palliate care patients. This is because the intention of the study was to find out how many people become long term users when we don’t want them to be long term users.  The problem is that this data set doesn’t include the patient diagnosis. To get around this, they excluded patients who died within 1 year of this first opioid prescription assuming that these patients might have been palliative care patients.
  • They also excluded anyone under the age of 11 because they are thought to be at low risk of chronic use and because this age group would mostly be prescribed opiates in the form of antitussive medication. 
  • Another issue they had with the data was that all they had to work with was the number of pills prescribed and the dose of the pills. So they couldn’t work out from that whether it was a PRN prescription or whether they were prescribed to take 2 tablets per day or 5 tablets per day. But they used a different approach to get around this. A good marker of what dose they were using was how many times they refilled a script within the first 30 days of this first script.  So they know the dose of the pills and the amount of pills that were prescribed, and they know now how long it took them to refill the script they could now figure out what dose they were using. 

Results

  • Of the 536,767 patients who were prescribed an opiate for the first time, 26,785 became long term opioid users. Which makes 5%. 
  • 85% of these first prescriptions were combinations of opiates with paracetamol. In Australia we have a combination product of paracetamol and codeine known as Panadein or Panadein Forte. America seem to have a lot more combination options: they have acetaminophen and hydrocodone, acetamenophine and oxycodone as well as acetaminophen and codeine.
  • The more repeat fills they had in the first 30 days after the initial prescription, the more likely they were to become chronic users: The risk of chronic use went from 2.9% if they just filled that first script in the first 30 days, to 10% if they had another refill in the first 30 days, to 26.1% if they had 4 or more refills in the first 30 days. 
  • Now here is possibly the most interesting finding in the entire study: those who were started on long acting opioids had a much higher chance of chronic use than those started on short acting opiates. It was 25% versus 3.5%. 

Bottom Line

There is a 5% risk that a patient will become a chronic opioid user after being given their first script for an opioid medication. The likelihood of long term use increase greatly as the number of script refills within the first 30 days increased – From 2.9% with just that 1 opioid script fill, to 26% if they filled 4 or more.  Initial prescribing of extended release preparations are associated with much higher chronic use rates compared to immediate release forms (25% versus 3.5%)

 

References:

Links:

youtube.com/drdanmd

 

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