Background/Purpose:  Caffeine’s action as an NSAID adjuvant are well understood, yet little clinical research has explored its effects on opioid analgesia. We present data from a large sample of fibromyalgia patients assessing the effect of caffeine use in the presence and absence of opioid analgesics.

Methods:  962 patients (67% female) presenting to a tertiary pain clinic and meeting the 2011 American College of Rheumatology (ACR) survey criteria for fibromyalgia were included. Patients completed the Brief Pain Inventory (BPI), Hospital Anxiety and Depression Survey (HADS), PROMIS fatigue measure, pain catastrophizing scale, and Oswestry Disability Index (ODI). Consumption of caffeinated beverages and opioid analgesics was assessed using a dichotomous item: patients indicated “yes” or “no” to daily consumption. General linear models were used to determine effect of caffeine use on independent measures. Gender and smoking status differed in univariate analysis and were controlled for as covariates. Adjusted mean differences (x) (standard error) are reported. Analyses were performed with SPSS 22.

Results:  568 (59%) patients were on current opioid therapy (66% female) and 394 (41%) were not (67% female). In patients on opioid therapy, caffeine consumers had significantly lower pain severity [F= 4.3, p= .04, x= .33(.16)], pain interference [F= 8.1, p< .001, x= 0.5(0.2)], fatigue [F= 14.2, p< .001, x= 2.5(0.7)], depression [F= 5.2, p= .01, x= 1.0(0.4)], catastrophizing [F= 11.0, p< .001, x= 3.8(1.2)] and disability [F= 12.9, p< .001, x= 3.3(0.9)] compared to non-caffeine consumers. Anxiety did not differ between caffeine groups. In the opioid negative group, caffeine consumers reported significantly less fatigue than non-consumers [F= 5.3, p= .02, x= 2.0(0.9)]. No other measures differed significantly between caffeine consumers and non-consumers in patients not on opioid therapy.

Conclusion:  Fibromyalgia patients on opioid therapy that also use caffeine reported significantly lower symptoms compared to patients that do not consume caffeine. However, in patients not on opioid therapy, caffeine consumers don’t share the same benefits seen in subjects on opioid therapy. These results suggest that consumption of caffeine in conjunction with opioid analgesics could possibly provide therapeutic benefits not seen with opioids or caffeine alone. Further research is needed to assess caffeine’s adjuvant effects on opioid analgesics in chronic pain.

ACR Meeting Abstracts - https://acrabstracts.org/abstract/influence-of-caffeine-on-opioid-analgesics-in-fibromyalgia/