title: The effect of oxcarbazepine in peripheral neuropathic pain depends on pain phenotype: a randomised, double-blind, placebo-controlled phenotype-stratified study.
abstract: In neuropathic pain it has been suggested that pain phenotype based on putative pain mechanisms may predict response to treatment. This was a randomised, double-blind, placebo-controlled, and phenotype-stratified study with 2 6-week treatment periods of oxcarbazepine (1800-2400mg) and placebo. The primary efficacy measure was change in median pain intensity between baseline and the last week of treatment measured on an 11-point numeric rating scale, and the primary objective was to compare the effect of oxcarbazepine in patients with and without the irritable nociceptor phenotype as defined by hypersensitivity and preserved small nerve fibre function determined by detailed quantitative sensory testing. Ninety-seven patients with peripheral neuropathic pain due to polyneuropathy, surgical or traumatic nerve injury, or postherpetic neuralgia were randomised. The intention-to-treat population comprised 83 patients: 31 with the irritable and 52 with the nonirritable nociceptor phenotype. In the total sample, oxcarbazepine relieved pain of 0.7 points (on a numeric rating scale 0-10; 95% confidence interval [CI] 0.4-1.4) more than placebo (P=0.015) and there was a significant interaction between treatment and phenotype of 0.7 (95% CI 0.01-1.4, P=0.047). The number needed to treat to obtain one patient with more than 50% pain relief was 6.9 (95% CI 4.2-22) in the total sample, 3.9 (95% CI 2.3-12) in the irritable, and 13 (95% CI 5.3-∞) in the nonirritable nociceptor phenotype. In conclusion, oxcarbazepine is more efficacious for relief of peripheral neuropathic pain in patients with the irritable vs the nonirritable nociceptor phenotype.
authors.affiliation: Department of Neurology, Odense University Hospital, Odense, Denmark.
authors.forename: Dyveke T
authors.initials: DT
authors.lastname: Demant
authors.affiliation: Danish Pain Research Centre, Aarhus University Hospital, Aarhus, Denmark.
authors.forename: Karen
authors.initials: K
authors.lastname: Lund
authors.affiliation: Department of Pain Medicine, Bergmannsheil Hospital, Ruhr-University Bochum, Bochum, Germany.
authors.forename: Jan
authors.initials: J
authors.lastname: Vollert
authors.affiliation: Department of Pain Medicine, Bergmannsheil Hospital, Ruhr-University Bochum, Bochum, Germany.
authors.forename: Christoph
authors.initials: C
authors.lastname: Maier
authors.affiliation: Lundbeck A/S, Copenhagen, Denmark; Department of Physiology and Pharmacology, Karolinska Institute, Stockholm, Sweden.
authors.forename: Märtha
authors.initials: M
authors.lastname: Segerdahl
authors.affiliation: Danish Pain Research Centre, Aarhus University Hospital, Aarhus, Denmark.
authors.forename: Nanna B
authors.initials: NB
authors.lastname: Finnerup
authors.affiliation: Danish Pain Research Centre, Aarhus University Hospital, Aarhus, Denmark.
authors.forename: Troels S
authors.initials: TS
authors.lastname: Jensen
authors.affiliation: Department of Neurology, Odense University Hospital, Odense, Denmark. Electronic address: soeren.sindrup@ouh.regionsyddanmark.dk.
authors.forename: Søren H
authors.initials: SH
authors.lastname: Sindrup
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002220:Carbamazepine / Q000031:analogs & derivatives* / Q000627:therapeutic use; D018592:Cross-Over Studies; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D000078330:Oxcarbazepine; D010146:Pain / Q000188:drug therapy* / Q000209:etiology*; D010147:Pain Measurement; D010523:Peripheral Nervous System Diseases / Q000150:complications*; D016896:Treatment Outcome; D061567:Voltage-Gated Sodium Channel Blockers / Q000627:therapeutic use*; D055815:Young Adult
chemical_list: D061567:Voltage-Gated Sodium Channel Blockers; D002220:Carbamazepine; D000078330:Oxcarbazepine
keywords: Neuropathic pain; Oxcarbazepine; Pain phenotype; Pharmacological management; Sensory profile