The Pains of Pills

Here's a little write-up of an article from Nature Neuroscience from my Behavioral Neuroscience class. It's supposed to be in the style of a "pop science" article for the masses, which pretty much meant paraphrasing the more technical stuff into digestible prose. Enjoy!

Taking a Look at Painkillers

New evidence shows that opioids could potentially disturb activity in some of the learning areas of the brain in the long-term

By Gabriel Ibagon

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Engulfed in the depths of pill culture, Americans are in the depths of a love affair with prescription pain killers. Whether these pills are prescribed to help handle physical pain, or whether people abuse them for their euphoric effects, many people take prescription pain killers without much concern for their long term effects. Brady K. Atwood, David A. Kupferschmidt, and David M. Lovinger have just released a study investigating how opioids, a common form of painkillers, may have long-term consequences on the brain, in the hope that this information can better help us deal with problems surrounding opioid use and abuse.

The National Survey on Drug Use and Health estimates that 1.9 million Americans are currently abusing opioids. Experts believe that the increasing trend of painkiller abuse has come about because of the continuously increasing amount of prescriptions handed out by doctors (from about 75.5 to 209.5 million in the last 20 years), as well as the trend of misperceptions of the dangers of these drugs (National Institute of Drug Abuse). Many people may assume that drugs handed out by doctors would be less harmful than other sorts of illicit recreational drugs. However, prescription painkillers carry just as much potential for harm as many other drugs that are misused. Research efforts have been embarked to further understand what exactly happens to your brain when you take these drugs, and how we can then translate this information to the public to inform them about any adverse effects.  Atwood et al. have investigated the effects of opioid abuse on specific aspects of the brain, which may hint us towards the negative effects people may experience after several years of opioid abuse.

Published in Nature Neuroscience under the title, “Opioids induce dissociable forms of long-term depression of excitatory inputs to the dorsal striatum,” this study reports that opioids caused several connections in the brains of rats to be less efficient in the aftermath of opioid administration. The researchers used oxycodone, a common prescription painkiller, to see how the dorsal striatum in rats is modified – understanding the “plasticity” of the dorsal striatum after drug use. These rats were then killed and had their brains examined to search for neurological changes, which revealed that several of the opioid receptors in the dorsal striatum part of the brain experienced opioid-induced long-term depression (OP-LTD), which means that the synapses connecting to the striatum became less active. The overall effect of these changes are not known, but by looking at similar studies conducted with alcohol- and marijuana-induced disruptions to the dorsal striatum, scientists suspect that this may affect learning (especially helping us establish habits).

Although this may sound like a grim warning to stop taking your pain prescriptions, we should take a moment to consider what the implications of this research study are. The research has only been done on rats, so while these critters do serve as a good model to begin to understand how opioids work on the brain, we can’t necessarily generalize these findings to the human brain. The dosage used for the rats also seemed extraordinarily high; the rats were given 1mg of oxycodone per kg of body weight, where the usual human dose is around 0.2mg per kg of body weight. The rats were also only examined a few hours to a few days after a dose, which would probably show a different result than someone who takes pain medication every day for a few years. Lastly, the authors expressed their uncertainty about the cognitive and behavioral effects that opioids depression on the striatum would cause.

However, these findings are still significant in that they hint us towards the importance of further understanding the long-term effect of opioids on the brain. Not only are the prescription rates of opioid drugs skyrocketing, the abuse of these drugs is also following suit. As we struggle to find ways to prevent people from misusing these drugs in a potentially harmful manner, we must also try to extend our knowledge in order to understand and treat these potentially harmful effects. Furthermore, science can provide people with tools to educate the public about these drugs, to make our society much more informed and responsible when it comes to using substances. With the health of the public in mind, we must urge that science do all it can to understand the intricacies of opioid use.

 

References

Atwood, Brady K., Kupferschmidt, David A., and Lovinger, David M. (2014). Opioids induce dissociable forms of long-term depression of excitatory inputs to the dorsal striatum. Nature Neuroscience, 17.4. Retrieved from http://www.nature.com/neuro/journal/v17/n4/pdf/nn.3652.pdf.

National Institute on Drug Abuse. (2011). Prescription Drug Abuse: A Research Update from the National Institute on Drug Abuse. Retrieved from  http://www.drugabuse.gov/sites/default/files/prescription_1.pdf.

U.S Department of Health and Human Services. (2012). National Survey on Drug Use and Health: Summary of National Findings [Data file]. Retrieved from http://www.samhsa.gov/data/NSDUH/2012SummNatFindDetTables/NationalFindings/NSDUHresults2012.htm.