Does long-term opioid therapy reduce pain sensitivity of patients with chronic low back pain? Evidence from quantitative sensory testing.
BACKGROUND
Long-term opioid treatment has been used extensively in treatment of chronic low back pain (cLBP) in the last decades. However, there are serious limitations to the long-term efficacy of opioids and related side effects.


OBJECTIVE
In this study we investigated whether long-term opioid treatment changes pain sensitivity of patients with cLBP.


METHODS
A prospective, nonrandomized, cross-sectional study.


METHODS
Multidisciplinary pain management clinic, specialty referral center, university hospital in Germany.


METHODS
Using quantitative sensory testing (QST), we compared the pain sensitivity of the low back bilaterally among 3 groups: 35 patients with cLBP undergoing a long-term opioid therapy (OP); 35 patients with cLBP administered no opioids (ON), and 28 subjects with neither pain nor opioid intake (HC).


RESULTS
OP patients showed significantly higher bilateral thermal detection thresholds to warm stimuli on the back as compared to both ON (P = 0.009 for left low back, P = 0.008 for right low back) and HC subjects (P = 0.004 for left low back, P = 0.003 for right low back). Pain thresholds for cold and heat on the hand were similar in OP and ON groups; both showed, however, significantly reduced heat pain thresholds in comparison with HC participants (P = 0.012 for OP, P = 0.001 for ON). Factors such as age, sex, duration and dose of opioid intake, and self-reported pain intensity, but not depression and pain duration, correlated significantly with QST results.


CONCLUSIONS
Limitations include small numbers of patients with heterogeneous opioid therapy and the nonrandomized observational nature of the study.


CONCLUSIONS
The current study demonstrated that chronic opioid intake may only reduce the temperature sensitivity but not pain sensitivity measured by QST which is a useful tool in detecting characteristic changes in pain perception of patients with chronic low back pain after long-term opioid intake.
Department of Orthopaedic Surgery and Traumatology, Heidelberg University Hospital, Heidelberg, Germany. haili.wang@med.uni-heidelberg.de
Haili
H
Wang
Christian
C
Fischer
Gang
G
Chen
Nina
N
Weinsheimer
Simone
S
Gantz
Marcus
M
Schiltenwolf
D000701:Analgesics, Opioid / Q000008:administration & dosage*; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D017116:Low Back Pain / Q000188:drug therapy*; D008297:Male; D008875:Middle Aged; D010147:Pain Measurement; D017288:Pain Threshold / Q000187:drug effects*; D013697:Thermosensing / Q000187:drug effects*
D000701:Analgesics, Opioid