Features

Our growing addiction to prescription painkillers

by Bianca Nogrady

Prescription painkillers are some of the most commonly misused drugs in Australia. So why are doctors prescribing these medications in increasing numbers? And how can people with chronic pain safely use prescription opioids?



[Image source: iStockPhoto | milanfoto ]

When talking about the problems of illicit drug use in Australia, conversations will tend to focus on ice, heroin, ecstasy and similar drugs.

But one class of drugs rarely gets a mention, despite the fact that it's now overtaking heroin as the cause of calls to drug treatment services. Perhaps that's because there's a good chance you've tried it, and a very good chance that your doctor prescribed it to you.

Prescription pain-relieving opioids, such as morphine and oxycodone, are fast becoming the top drugs of misuse in Australia. For example, one Victorian alcohol and drug counselling helpline now receives more than twice as many calls about prescription opioids as they do about heroin.

At the Sydney Medically Supervised Injecting Centre, more than three times as many visits each month are for the injection of crushed opioid tablets when compared to heroin.

Prescription opioids are not only an issue in Australia. In the United States, prescription opioids have earned the nickname 'hillbilly heroin', and their public health impact is now being likened to that of diabetes.

No typical user

There is no typical user, or typical scenario for prescription opioid misuse, although most people seeking help for prescription opioid addiction have been prescribed medication for pain relief, says Dr Matthew Frei, clinical director of Victoria's Turning Point Alcohol and Drug Centre.

"There's a spectrum of aberrance or dysfunction or problems associated with the medications," says Frei.

"They range from gradual dose escalation to a dose that is causing some discomfort either for the patients, their doctor, and/or the regulators; to people who are really dysfunctional and might be attempting to get the medications from multiple doctors, they might be purchasing medications on grey or black markets, and even in severe cases, injecting, selling or trading the medication."

Frei says most people seeking treatment for prescription opioid addiction were originally prescribed the medication  as opposed to those who have come by the medication through illicit means  which highlights a major part of the problem with opioids, and the reason why we now find ourselves in this epidemic of misuse.

Prescription rates skyrocket

Opioid prescriptions have increased dramatically in the past two decades. The supply of oxycodone increased from 95.1kg in 1999 to 1270.7kg in 2008, and prescriptions increased 20.1 per cent from 2005-06 to 2006-07 alone.

The picture is the same for morphine. One study reported a 89 per cent increase in the rate of morphine prescription per person between 1995 and 2003.

This begs the question of why so many more prescription opioids are being used. Emergency medicine specialist Dr David Caldicott from Canberra's Calvary Hospital says there is a clear pattern of overprescribing, and inappropriate prescribing, of opioids in Australia, and some of that is being driven by patients themselves.

"I think there is perhaps an expectation or sense that pain from whatever painful condition can be obliterated, and that may be contributing to the overprescription of these drugs," Caldicott says.

Doctors are also under increasing pressure to dispense quick solutions.

"In an increasingly time-poor medical environment  where to get optimal pain relief you want to sit them down, tell people what exercises to go through, what other non-pharmaceutical tricks they could use to minimise their pain  it is very tempting just to give them a pack of pills and send them on their way," he says.

More harm than good

However in many cases, this pack of pills is likely to do far more harm than good. One particular issue is that it's possible to become tolerant of the effects of these drugs, and therefore require higher and higher doses to achieve the same effects.

Another problem is that opioids, like all pharmaceuticals, come with side effects, and the one causing the most problems is its impact on our respiratory system. In some situations, this can be deadly.

"If you have a background of chronic respiratory disease and you are just on the edge of surviving as far as your breathing is concerned, and you broke your leg, and somebody got the dosing too enthusiastically then there could be a problem," Caldicott says.

"If you are taking any other medications that cause respiratory depression, they can accentuate the effects, and there are plenty of ways where a fairly normal dose for a 25-year-old 80 kilogram man could really knock a 50 kilogram 75-year-old off their perch."

Prescription opioids are also featuring more prominently than ever before in the overdose figures, according to Professor Louisa Degenhardt, professor of epidemiology at the National Drug and Alcohol Research Centre at the University of New South Wales.

"Heroin is still the most common [cause of overdose] of any single opioid; it accounts for about 30 per cent of overdoses, but it used to account for 70 per cent of opioid overdoses, so pharmaceutical opioids are now comprising the remaining 70 per cent," Degenhardt says.

Figures from Victoria showed that the detection of oxycodone in deaths reported to the Victorian Coroner increased 21-fold from 2000 to 2009.

While overdoses in older patients with pain are thought to be largely deliberate, overdoses in younger individuals generally occur among injecting drug users, who often crush the tablets to snort or inject them.

"Often tablets have a controlled release mechanism so when you swallow it, it gives you less of a high and more of a sustained level of coverage of pain," Degenhardt says.

"But when you tamper with a tablet, that mechanism is overcome so basically you get the whole dose at once."

In response to this kind of misuse, drug manufacturers are reformulating the tablets to make them harder to tamper with.

How useful are these medications?

There are also serious questions about whether opioids such as oxycodone and morphine do actually help in the case of long-term, chronic, non-cancer pain, says pain medicine specialist Professor Milton Cohen from Sydney's St Vincents Hospital.

"The more liberal prescription [of opiods] reflects the better recognition of the problem of chronic non-cancer pain in particular and the desire to do something more about it, although to rely on medications alone in that context is not going to work," Cohen says.

Chronic non-cancer pain  and indeed pain generally  is still relatively poorly understood, he says, and is under-represented in medical education, largely because of its complexity.

"Chronic pain is not a reliable guide to a body disease, so it's hard for medicines to come to grips with."

For example chronic back pain, a scenario that would often lead to the prescription of opioids, is often not due to a clear and treatable disease; it often presents in people who have other medical problems, including a history of psychological illness.

"It's a much more complex phenomenon than just 'something is wrong with your back', and the reliance on using medications to treat that, often in a multiple-medication situation, has led to the problem," Cohen says.

"When somebody says 'my pain is getting worse', often what they mean is 'my life is getting worse'."

Addiction medicine physician Professor Yvonne Bonomo from St Vincents Hospital in Melbourne says people may not even realise they are becoming addicted to their opioid pain relief.

"Some are on prescription opioids and don't realise they are becoming dependent, then suddenly their supply runs out and their doctor is not prepared to prescribe anymore, or they go into hospital for something else and stop their medications and experience withdrawal syndrome," she says.

One solution to avoiding this is to have a clear plan from the beginning about how long someone is going to be taking opioids, Bonomo says.

"Having an end date in mind when you start is very important," she says.

"There are guidelines around longer term use now and so doctors are being educated about that but really the bottom line is before you start the opioids you have a plan for how long approximately you plan to provide this medication, how long you think it will be needed, and what other aspects of pain management are going to take place."