Studies Warn of Pregabalin Deaths

By Pat Anson, Editor

Two new studies – one in Canada and one in Australia – should give pause to patients who use opioids and pregabalin (Lyrica), an anticonvulsant medication increasingly prescribed for fibromyalgia, neuropathy and other chronic pain conditions. Both studies found a number of overdose deaths that involve – but were not necessarily caused -- by pregabalin.

The Canadian study, published in the Annals of Internal Medicine, looked at over 1,400 patients in Ontario on opioid medication from 1997 to 2016 who died from opioid-related causes. Another group of over 5,000 surviving opioid patients was used as a control group.

Researchers found that patients who were co-prescribed opioids and pregabalin had a significantly higher risk of an overdose.

The risk of death was over two times higher for patients receiving opioids and a high dose of pregabalin (over 300mg) compared to those who took opioids alone.

Patients on a low or moderate dose of pregabalin also had a heightened risk, although not as large.

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Researchers say pregabalin has a sedative effect and may interact with opioids in ways that increase respiratory depression. Few doctors and patients are aware of the risk, even though over half of Ontario residents who begin pregabalin therapy are also prescribed an opioid.

"There is an important drug interaction between opioids and pregabalin that can lead to increased risk of fatal overdose, particularly at high doses of pregabalin," lead author Tara Gomes, PhD, of the Institute for Clinical Evaluative Sciences (ICES) and St. Michael's Hospital in Toronto, told MedPage Today.

"Clinicians should consider carefully whether to prescribe opioids and pregabalin together. If they decide that both medications are clinically appropriate, they should start with low doses and monitor their patients closely."

Lyrica (pregabalin) and Neurontin (gabapentin) are both made by Pfizer and belong to a class of anticonvulsant nerve medication called gabapentinoids. Sales of gabapentinoids have tripled in recent years, in part because of CDC prescribing guidelines that recommend the drugs as alternatives to opioid medication.  

U.S. health officials have only recently started looking into the misuse and abuse of gabapentinoids, which are increasingly used by addicts to enhance the euphoric effects of heroin and other illicit opioids. While gabapentin  has a warning label cautioning users who take the drug with opioids, there is no similar warning for pregabalin.

“Although current product monographs for gabapentin contain warnings about serious adverse events when this agent is combined with opioids, those for pregabalin do not. The importance of our finding warrants a revision of the pregabalin product monographs,” wrote Gomes.

Pregabalin Abuse in Australia

Health officials in Australia are also concerned about the growing use of pregabalin.  Researchers at the NSW Poisons Information Centre say poisoning cases involving pregabalin rose from zero in 2005 to 376 cases in 2016.

“Our study shows a clear correlation between the rapid and continuous rise of pregabalin dispensing and an increase in intentional poisonings and deaths associated with pregabalin,” said lead author Dr. Rose Cairns, a specialist at the NSW Poisons Information Centre.

According to the Australian Journal of Pharmacy (AJP), there have been 88 recorded deaths associated with pregabalin in recent years. Most of the deaths involved young, unemployed males who had a history of substance abuse, particularly with opioids, benzodiazepines, alcohol and illicit drugs.

“We believe that Australian doctors may not be aware of the abuse potential of pregabalin,” Cairns said. “Most patients who are prescribed this medication are in the older population but the group who are at high risk of overdosing are much younger. These people are likely to have been prescribed pregabalin despite having a history of substance abuse.”

According to researchers, up to two-thirds of people who intentionally misused pregabalin had a prior documented substance abuse history. “Prescribers need to consider this growing body of evidence that pregabalin has abuse potential before prescribing, especially to patients with substance abuse history,” said Cairns.

Pfizer did not respond to a request for comment on the Canadian and Australian studies.

One Million Australians Abuse Rx Drugs

By Pat Anson, Editor

Like the United States, Australia is struggling to find answers to a growing addiction and overdose crisis – and restricting access to opioid pain medication is the favored solution.

A new report by the Australian Institute of Health and Welfare (AIHW) found that a million Australians -- about 4.7% of the population – abused a prescription drug in 2016. That’s up from 3.7% in 2007.   

‘Over the past decade, there has been a substantial rise in the number of deaths involving a prescription drug, with   drug-induced deaths more likely to be due to prescription drugs than illegal drugs,’ said AIHW spokesperson Matthew James.

In 2016, there were 1,808 drug overdose deaths in Australia, but the leading cause was not pain medication. Benzodiazepines, a class of anti-anxiety medication that includes Xanax and Valium,  were involved in 663 overdoses -- compared to 550 deaths linked to opioid medications such as oxycodone and codeine.

Recent reports from Florida and Pennsylvania also show that overdoses linked to "benzos" outnumber those from pain medication, although you rarely hear about that in today’s anti-opioid climate.

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Unlike the United States, where prescriptions for opioid medication have been in decline for several years, in Australia they rose by 24% from 2010 to 2015 – driven largely by a 60% increase in the rate of prescriptions for oxycodone.

Like their American counterparts, Australian regulators and health officials are responding to the overdose crisis by reducing access to opioid medication. Starting in February 2018, Australians will need a prescription for codeine, which is now widely available in over-the-counter analgesic and flu medications.  Australia is also introducing a national prescription drug monitoring system.

Economic despair and social isolation appear to be playing major roles in Australia's overdose crisis, just as they are in the United States. Earlier this year, a nationwide survey found that people living in remote, rural areas of Australia were almost twice as likely as those living in major cities to use pharmaceutical drugs for non-medical purposes.

“This finding also held true for Australians living in the most disadvantaged socio-economic areas, with 6 percent having recently misused pharmaceuticals compared with 4.2 percent of those in the most advantaged areas,” James said.

Australians who misused prescription drugs were also more likely to experience mental illness, chronic pain and psychological distress compared with those who did not misuse them.