Ontario opioid prescriptions routinely exceeded dosage guidelines, study finds

Nearly a quarter of first-time opioid prescriptions in Ontario from April 2015 to March 2016 exceeded recommended dose limits introduced in 2017.

Researchers say 23.9 per cent of initial opioid prescriptions in Ontario during that time had a daily dose of more than 50 milligram morphine equivalents.

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That's more than the threshold set last year for North American physicians treating chronic non-cancer pain with opioids like oxycodone, hydromorphone and the fentanyl patch.

We need to think about alternative pain management options.- Tara Gomes, medical researcher

The year-old guidelines suggest opioids be restricted to less than the equivalent of 90 milligrams of morphine per day, and ideally to less than 50 mg. They replaced previous guidelines released in 2010 that suggested doctors could use a "watchful dose" of the equivalent of 200 mg of morphine daily.

Researchers at the Institute for Clinical Evaluative Sciences and St. Michael's Hospital examined initial opioid prescriptions for more than 650,000 Ontarians. Their work was published Wednesday in the journal Pain.

Lead author Tara Gomes says the findings highlight the need to consider alternative pain management options for some patients, such as physiotherapy and cognitive behavioural therapy.

Dental pain accounted for nearly one in four new opioid prescriptions, but the study found these were "generally of short duration and low dose."

Meanwhile, one in six were for postsurgical pain, and more than 40 per cent of those patients were prescribed more than the equivalent of 50 mg of morphine daily. At least 25 per cent of prescriptions for hip and knee surgery were the equivalent of 90 mg of morphine daily, or more.

Other treatments may help reduce opioiduse

Gomes says Ontarians taking an opioid for the first time for knee, hip and shoulder surgeries and for Caesarean sections received among the highest doses.

"Across all clinical indications, a high percentage of people received daily doses of more than 50MME and prescription lengths exceeding seven days, a combination which has been associated with opioid-related adverse events and long-term opioid use," Gomes said Wednesday in a release.

"Given this, we need to think about alternative pain management options. This data can help us understand the types of services like physiotherapy and cognitive behavioural therapy that might be appropriate to help avoid our reliance on opioids for some indications."

Researchers identified six main reasons for taking opioids: the most frequent reason was dental pain at 23.2 per cent of prescriptions, followed by postsurgical pain at 17.4 per cent, musculoskeletal pain at 12.0 per cent, trauma-related pain at 11.2 per cent, cancer or palliative care at 6.5 per cent, and other types of pain at 17.7 per cent.

Overall, 12 per cent or 78,481 individuals could not be linked to any of the six groups.

Gomes says one in eight Ontarians was dispensed an opioid in 2016 and that Ontario has seen a four-fold increase in overdose deaths in the last 25 years.