Predicting drug efficacy in chronic low back pain by quantitative sensory tests.
- Schliessbach J Department of Anesthesiology and Pain Medicine, Inselspital, Bern University Hospital, University of Bern, Switzerland.
- Siegenthaler A Chronic Pain Management, Lindenhof Hospital, Lindenhof Group Bern, Switzerland.
- Bütikofer L CTU Bern, and Institute of Social and Preventive Medicine (ISPM), University of Bern, Switzerland.
- Vuilleumier P Department of Anesthesiology and Pain Medicine, Inselspital, Bern University Hospital, University of Bern, Switzerland.
- Jüni P Department of Medicine, Applied Health Research Centre (AHRC), Li Ka Shing Knowledge Institute of St. Michael's Hospital, University of Toronto, ON, Canada.
- Stamer U Department of Anesthesiology and Pain Medicine, Inselspital, Bern University Hospital, University of Bern, Switzerland.
- Arendt-Nielsen L Centre of Sensory Motor Interaction SMI, University of Aalborg, Denmark.
- Curatolo M Centre of Sensory Motor Interaction SMI, University of Aalborg, Denmark.
- 2018-01-25
Published in:
- European journal of pain (London, England). - 2018
Adult
Aged
Analgesics
Clobazam
Cross-Over Studies
Double-Blind Method
Electric Stimulation
Female
Humans
Imipramine
Low Back Pain
Male
Middle Aged
Oxycodone
Pain Measurement
Pain Threshold
Pressure
English
BACKGROUND
Drugs are prescribed for chronic low back pain without knowing in advance whether a patient will respond to them or not. Quantitative sensory tests (QST) can discriminate patients according to sensory phenotype, possibly reflecting underlying mechanisms of pain processing. QST may therefore be a screening tool to identify potential responders to a certain drug. The aim of this study was to investigate whether QST can predict analgesic effects of oxycodone, imipramine and clobazam in chronic low back pain.
METHODS
Oxycodone 15 mg (n = 50), imipramine 75 mg (n = 50) and clobazam 20 mg (n = 49) were compared to active placebo tolterodine 1 mg in a randomized, double-blinded, crossover fashion. Electrical, pressure and thermal QST were performed at baseline and after 1 and 2 h. Pain intensity was assessed on a 0-10 numeric rating scale every 30 min for up to 2 h. The ability of baseline QST to predict pain reduction after 2 h was analysed using linear mixed models. Genetic variants of drug-metabolizing enzymes and genes affecting pain sensitivity were examined as covariables.
RESULTS
No predictor of analgesic effect was found for oxycodone and clobazam. Thermal QST was associated with analgesic effect of imipramine: patients more sensitive to heat or cold were more likely to experience an effect of imipramine. Pharmacogenetic variants and pain-related candidate genes were not associated with drug efficacy.
CONCLUSIONS
Thermal QST have the potential to predict imipramine effect in chronic low back pain. Oxycodone and clobazam effects could not be predicted by any of the selected QST or genetic variants.
SIGNIFICANCE
Predicting drug efficacy in chronic low back pain remains difficult. There is some evidence that patients more sensitive to heat and cold pain respond better to imipramine.
Drugs are prescribed for chronic low back pain without knowing in advance whether a patient will respond to them or not. Quantitative sensory tests (QST) can discriminate patients according to sensory phenotype, possibly reflecting underlying mechanisms of pain processing. QST may therefore be a screening tool to identify potential responders to a certain drug. The aim of this study was to investigate whether QST can predict analgesic effects of oxycodone, imipramine and clobazam in chronic low back pain.
METHODS
Oxycodone 15 mg (n = 50), imipramine 75 mg (n = 50) and clobazam 20 mg (n = 49) were compared to active placebo tolterodine 1 mg in a randomized, double-blinded, crossover fashion. Electrical, pressure and thermal QST were performed at baseline and after 1 and 2 h. Pain intensity was assessed on a 0-10 numeric rating scale every 30 min for up to 2 h. The ability of baseline QST to predict pain reduction after 2 h was analysed using linear mixed models. Genetic variants of drug-metabolizing enzymes and genes affecting pain sensitivity were examined as covariables.
RESULTS
No predictor of analgesic effect was found for oxycodone and clobazam. Thermal QST was associated with analgesic effect of imipramine: patients more sensitive to heat or cold were more likely to experience an effect of imipramine. Pharmacogenetic variants and pain-related candidate genes were not associated with drug efficacy.
CONCLUSIONS
Thermal QST have the potential to predict imipramine effect in chronic low back pain. Oxycodone and clobazam effects could not be predicted by any of the selected QST or genetic variants.
SIGNIFICANCE
Predicting drug efficacy in chronic low back pain remains difficult. There is some evidence that patients more sensitive to heat and cold pain respond better to imipramine.
- Language
-
- English
- Open access status
- bronze
- Identifiers
-
- DOI 10.1002/ejp.1183
- PMID 29363217
- Persistent URL
- https://sonar.ch/global/documents/14605
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