Caffeine as an opioid analgesic adjuvant in fibromyalgia

Abstract

Background

Caffeine’s properties as an analgesic adjuvant with nonsteroidal anti-inflammatory drugs/acetaminophen are well documented. However, little clinical research has explored caffeine’s effects on opioid analgesia. This study assessed the effects of caffeine consumption on pain and other symptoms in opioid-using and nonusing chronic pain patients meeting the survey criteria for fibromyalgia.

Materials and methods

Patients presenting to a university-based pain clinic completed validated self-report questionnaires assessing symptoms. Patients (N=962) meeting the fibromyalgia survey criteria were stratified by opioid use and further split into groups based on caffeine amount consumed per day (no caffeine, or low, moderate, high caffeine). Analysis of covariance with Dunnett’s post hoc testing compared pain and symptom severity between the no caffeine group and the caffeine consuming groups.

Results

In opioid users, caffeine consumption had modest but significant effects on pain, catastrophizing, and physical function. Lower levels of pain interference were associated with low and moderate caffeine use compared to no caffeine intake. Lower pain catastrophizing and higher physical function were observed in all caffeine dose groups, relative to the no caffeine group. Lower pain severity and depression were observed only in the moderate caffeine group. In opioid nonusers, low caffeine intake was associated with higher physical function; however, no other significant effects were observed.

Conclusion

Caffeine consumption was associated with decreased pain and symptom severity in opioid users, but not in opioid nonusers, indicating caffeine may act as an opioid adjuvant in fibromyalgia-like chronic pain patients. These data suggest that caffeine consumption concomitant with opioid analgesics could provide therapeutic benefits not seen with opioids or caffeine alone.

Keywords:

• caffeine
• fibromyalgia
• opioid analgesics
• pain
• analgesic adjuvant
• chronic pain

Acknowledgments

A portion of this work was reported at the 2013 American Pain Society meeting. This work was funded by the Department of Anesthesiology, University of Michigan.

Disclosure

Dr Hassett is a consultant for Precision Health Economics and Happify. She has also had research funded by Bristol-Myers Squibb and Pfizer. Dr Brummett is a consultant for Tonix and has research funded by Neuros Medical. Dr Harris consults with and has research funded by Pfizer. Dr Clauw is a consultant for Abbott Pharmaceutical Products Division, Cerephex, Eli Lilly and Company, Forest Laboratories, Johnson & Johnson, Merck and Company, Pfizer, Purdue Pharma, Samumed, Theravance, Tonix, UCB, and Zynerba. Dr Harte has received research funding from Cerephex, Forest Laboratories, and Merck and served as a consultant for Pfizer, Analgesic Solutions, Aptinyx, and deCode Genetics.

The authors declare no other conflicts of interest and no competing financial interests with this work.