Saturday, 3 November 2012

Opioids: the real opium of the masses


Opioids are strong pain killing drugs that mimic the body’s own chemicals. Examples of prescription opioids include heroin (which metabolises to morphine and was banned after 1925), morphine, oxycodone and hydrocodone. As pain killers for acute pain, opioids work. However, over longer periods they become less effective, have more adverse effects, and can lead to tolerance, dependence, addiction, increased pain, and death. Here are some facts about long-term opioid use.

  • The use of opioids for chronic non-cancer pain is not well supported by clinical trials (Cochrane review, Clinical Journal of Pain review)
  • Rates of opioid prescription are increasing (here and here)
  • The increase in prescription rates has been partly attributed to aggressive marketing and under-reporting of harmful effects and rates of addiction by the manufacturer, leading to several lawsuits and fines in the USA (here)
  • Opioids lose effectiveness over time (here)
  • Chronic opioid use leads to increased side effects (nausea, headache, constipation and depression of the central nervous system), to increased tolerance and drug dependence, and it may also lead to ‘hyperalgesia’: an increased sensitivity to pain (here, here, here and here)
  • Increasing prescription rates are associated with increased rates of opioid abuse and addiction (here)
  • There were 2.4 million opioid abusers in the US in 2010, most from prescription opioids, and the number of new abusers increased 225% between 1992 and 2000 (here)
  • Opioid prescription rates are higher amongst the poor and unemployed (here and here)
  • Deaths (intentional and non-intentional) from prescription opioids are associated with social disadvantage (here)
  • Deaths from opioids are increasing and are currently responsible for more deaths than either cocaine or heroin in the US (here) and in Australia (here)
  • Prescription opioids were responsible for 14,459 overdose deaths in the US in 2007 compared to 4,041 in 1999 (here), and 475,000 emergency room visits in 2009 (here)
  • Opioids are often given for chronic back pain, and they are commonly given (long-term) after spine fusion surgery. These studies (here and here) report rates of chronic opioid use of 70% - 80% after spine fusion surgery
  • Opioids are the biggest cause of loss of life after spine fusion surgery (usually in young patients) (here) and are associated with worse functional outcomes after spine surgery (here)


The bottom line
1. Opioids may not be effective for chronic non-cancer pain, and their use in such patients is associated with side effects, tolerance, dependence, and addiction.
2. Despite this, prescription opioid use is increasing and with that, the rates of opioid abuse and opioid related death are also increasing.
3. Harms from prescription opioids are over-represented in the socially disadvantaged.

7 comments:

  1. I couldn't agree more with your analysis of the abuse of these dangerous drugs. A couple points I'd add:

    1. Many of the spinal fusion surgeries that lead to chronic opioid dependence are totally unnecessary. The Dartmouth Atlas Project has found 20-fold variations in spinal fusions in different communities across America. These aren't harmless interventions, as opioid dependence can lead to premature death, as you document; and

    2. Animal studies have shown that opioids can cause tumors to spread throughout the body. Since many of us harbor latent cancers that are undetected, this is a hidden threat with enormous consequences. Perhaps public fear of cancer can be marshaled to raise awareness of the risks of opioids and temper their use.

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    1. Thanks John,

      You don't need to convince me about spine fusions, see my earlier blog post here: http://doctorskeptic.blogspot.com.au/2012/08/is-lumbar-spine-fusion-just-placebo.html

      I am not aware of a clinical link between opioids and cancer, and I would discard any animal study like that unless it is supported by some clinical evidence, as most animal studies are not translatable to humans.

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    2. Here's a link to an article about this finding:

      http://theramatch.com/therapy-news/morphine-may-help-tumors-spread-in-cancer-patients

      To quote: "Morphine can increase tumor cell proliferation, inhibit the immune system,promote the growth of new blood vessels (angiogenesis) that feed tumors and decrease barrier function."

      While it may or may not translate into humans, why take the risk? As a patient, it's something I'd want to know.

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    3. Thanks for the link John, interesting area of research.

      As the evidence stands, I think the risk of tumour spread/growth is small, and it needs to be weighed against the benefit from pain relief in cancer.

      I also think that there are enough documented clinical harms and evidence of lack of effectiveness from chronic opioid use to think twice before prescribing or using them, without having to take into account theoretical harms.

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  2. I have several concerns about the anti-opioid movement, not the least of which is its close ties to pharmaceutical companies keen to swap out relatively cheap pain management drugs with expensive and even less supported options. It also has very unfortunate ties to the war on drugs (a thoroughly failed venture with masses of clinical data to prove that case).

    And while trial evidence may be sparse for its use in non-cancer pain management, the epidemiological evidence would suggest it is more well tolerated than not and has long-term value in supporting quality of life for many with serious pain. Furthermore, as one example, there is good trial evidence that the use of heavy-duty opiates for the management of neuralgias does not result in tolerance or dependency.

    There are indeed abusers of prescription drugs. There are also those who are on disability or unemployment benefits for nefarious reasons as well. I am highly suspect of any argument that would suggest we punish the 90-95% of those for whom their quality of life depends upon access to these drugs just because we think that doing so will somehow help abusers to stop abusing.

    And what is to happen to all those poor and disadvantaged (most likely to be on opiates and most likely to die either intentionally or unintentionally from said opiates) when we successfully remove these relatively cheap pain management options altogether?

    Pregabalin and gabapentin are heavily marketed for neuralgias and spinal chord fusion surgery. I am sure it is coincidence that a prescription of either of those will cost 200% more than hydromorphone, by way of comparison.

    The social consequences of under-medicating pain, as we see in numerous developing nations (estimated to be about 150 countries according to WHO - http://www.who.int/medicines/areas/quality_safety/access_Contr_Med/en/) is where we will be headed if we simply swallow the savvy bait and swap to more expensive prescription pain medication under the guise that there is a moral duty to avoid prescribing opiates.

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    1. Thanks Gwyneth,

      I agree that we should not be throwing out the baby with the bathwater. Opioids have a role; a clearer picture of when and how they should be used is what we need.

      However, I think that our expectation to have all discomfort relieved extends into pain management, where the expectations are often too high. Chronic pain is often more related to psychosocial factors, and these should be addressed rather than covering the symptoms with long term opioids.

      Also, the patients that I see who 'rely' on long term opioids have long since lost their pain trigger (an injury which has healed) and do surprisingly well a few weeks after quitting. But I accept that I am likely to be biased by the type of patients that I see.

      Pregabalin and gabapentin are interesting. I can't work out their true effectiveness yet because of conflicting reports and the likelihood of industry bias.

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  3. As a RN, I see opioid dependence on an almost daily basis. Usually in otherwise able-bodied people who are on disability. Other than use in cancer, these drugs should be discouraged.

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