Systemic lidocaine in pain due to peripheral nerve injury and predictors of response.
OBJECTIVE
To investigate the effects of IV lidocaine on spontaneous and evoked pain (allodynia and hyperalgesia) due to peripheral nerve injury (postherpetic neuralgia or nerve trauma) using quantitative sensory testing.


METHODS
The authors randomized 22 patients to receive lidocaine 5 mg/kg IV during 30 minutes or placebo in a double-blind crossover design and 16 patients subsequently received mexiletine on an open basis titrated from 400 to 1,000 mg per day (mean 737 mg/day).


RESULTS
Lidocaine induced a significant decrease in ongoing pain for up to 6 hours with a peak effect 60 to 120 minutes postinjection. The drug also decreased mechanical dynamic allodynia and static (punctate) mechanical allodynia/hyperalgesia, but not thermal allodynia and hyperalgesia. The effects of lidocaine and mexiletine on spontaneous pain intensity were significantly higher in patients with concomitant mechanical allodynia in comparison with those without allodynia.


CONCLUSIONS
These data indicate modality-specific antihyperalgesic effects of IV lidocaine in patients with peripheral nerve injury. Patients with mechanical allodynia may be good candidates for treatment with local anesthetic-like drugs and possibly with other sodium-channel blockers.
Attal
N
N
INSERM E-332, Centre d'Evaluation et de Traitement de la Douleur, Hôpital Ambroise Paré, AP-HP, and Université Versailles-Saint-Quentin, France.
Rouaud
J
J
Brasseur
L
L
Chauvin
M
M
Bouhassira
D
D
D000328:Adult; D000368:Aged; D000700:Analgesics / Q000008:administration & dosage / Q000627:therapeutic use*; D003080:Cold Temperature; D018592:Cross-Over Studies; D004311:Double-Blind Method; D005260:Female; D006358:Hot Temperature; D006801:Humans; D006930:Hyperalgesia / Q000188:drug therapy / Q000209:etiology; D007262:Infusions, Intravenous; D008012:Lidocaine / Q000008:administration & dosage / Q000627:therapeutic use*; D008297:Male; D008801:Mexiletine / Q000627:therapeutic use; D008875:Middle Aged; D009437:Neuralgia / Q000188:drug therapy / Q000209:etiology; D010146:Pain / Q000188:drug therapy* / Q000209:etiology; D017288:Pain Threshold / Q000187:drug effects; D059348:Peripheral Nerve Injuries; D010812:Physical Stimulation; D012684:Sensory Thresholds / Q000187:drug effects; D014110:Touch; D016896:Treatment Outcome
D000700:Analgesics; D008801:Mexiletine; D008012:Lidocaine