Featured Research

from universities, journals, and other organizations

Codeine could increase users' sensitivity to pain

Date:
September 12, 2013
Source:
University of Adelaide
Summary:
Using large and frequent doses of the pain-killer codeine may actually produce heightened sensitivity to pain, without the same level of relief offered by morphine, according to new research.

Using large and frequent doses of the pain-killer codeine may actually produce heightened sensitivity to pain, without the same level of relief offered by morphine, according to new research from the University of Adelaide.

Researchers in the Discipline of Pharmacology have conducted what is believed to be the world's first experimental study comparing the pain relieving and pain worsening effects of both codeine and morphine.

The University's Professor Paul Rolan, who is also a headache specialist at the Royal Adelaide Hospital, says codeine has been widely used as pain relief for more than 100 years but its effectiveness has not been tested in this way before.

"In the clinical setting, patients have complained that their headaches became worse after using regular codeine, not better," Professor Rolan says.

"Codeine use is not controlled in the same way as morphine, and as it is the most widely used strong pain reliever medication in the world, we thought it was about time we looked into how effective it really is."

In laboratory studies, University of Adelaide PhD student Jacinta Johnson found that codeine provided much less pain relief than morphine, but resulted in the same level of increased sensitivity to pain.

"Pain sensitivity is a major issue for users of opioid drugs because the more you take, the more the drug can increase your sensitivity to pain, so you may never quite get the level of relief you need. In the long term it has the effect of worsening the problem rather than making it better. We think that this is a particular problem in headache patients, who seem more sensitive to this effect," Ms Johnson says.

"Both codeine and morphine are opioids but codeine is a kind of 'Trojan horse' drug -- 10% of it is converted to morphine, which is how it helps to provide pain relief. However, despite not offering the same level of pain relief, we found that codeine increased pain sensitivity just as much as morphine."

Professor Rolan says while more research is needed, these laboratory findings suggest a potential problem for anyone suffering from chronic pain who needs ongoing medication.

"People who take codeine every now and then should have nothing to worry about, but heavy and ongoing codeine use could be detrimental for those patients who have chronic pain and headache," Professor Rolan says. "This can be a very difficult issue for many people experiencing pain, and it creates difficulties for clinicians who are trying to find strategies to improve people's pain."

Ms Johnson presented this research at the 2013 International Headache Congress in Boston, and her work is featured in this month's issue of Neurology Reviews.

A clinical trial testing a new approach to treating codeine-related headache is now being run by Professor Rolan.

The review itself can be found online at: http://www.neurologyreviews.com/the-publication/issue-single-view/codeine-and-morphine-may-increase-pain-sensitivity-equally/382d2c385b5e3154bbed15156f33e46c.html


Story Source:

The above story is based on materials provided by University of Adelaide. Note: Materials may be edited for content and length.


Cite This Page:

University of Adelaide. "Codeine could increase users' sensitivity to pain." ScienceDaily. ScienceDaily, 12 September 2013. <www.sciencedaily.com/releases/2013/09/130912092251.htm>.
University of Adelaide. (2013, September 12). Codeine could increase users' sensitivity to pain. ScienceDaily. Retrieved September 23, 2014 from www.sciencedaily.com/releases/2013/09/130912092251.htm
University of Adelaide. "Codeine could increase users' sensitivity to pain." ScienceDaily. www.sciencedaily.com/releases/2013/09/130912092251.htm (accessed September 23, 2014).

Share This



More Health & Medicine News

Tuesday, September 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Ebola Costs Keep Mounting

Ebola Costs Keep Mounting

Reuters - Business Video Online (Sep. 23, 2014) The WHO has warned up to 20,000 people could be infected with Ebola over the next few weeks. As Sonia Legg reports, the implications for the West African countries suffering from the disease are huge. Video provided by Reuters
Powered by NewsLook.com
Ebola Cases Could Reach 1.4 Million Within 4 Months

Ebola Cases Could Reach 1.4 Million Within 4 Months

Newsy (Sep. 23, 2014) Health officials warn that without further intervention, the number of Ebola cases in Liberia and Sierra Leone could reach 1.4 million by January. Video provided by Newsy
Powered by NewsLook.com
WHO: Ebola Cases to Triple in Weeks Without Drastic Action

WHO: Ebola Cases to Triple in Weeks Without Drastic Action

AFP (Sep. 23, 2014) The number of Ebola infections will triple to 20,000 by November, soaring by thousands every week if efforts to stop the outbreak are not stepped up radically, the WHO warned in a study on Tuesday. Duration: 01:01 Video provided by AFP
Powered by NewsLook.com
5 Ways Men Can Prevent Most Heart Attacks

5 Ways Men Can Prevent Most Heart Attacks

Newsy (Sep. 23, 2014) No surprise here: A recent study says men can reduce their risk of heart attack by maintaining a healthy lifestyle, which includes daily exercise. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Health & Medicine

Mind & Brain

Living & Well

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins