Intravenous lidocaine, amantadine, and placebo in the treatment of sciatica: a double-blind, randomized, controlled study.
OBJECTIVE
Sciatica is a neuropathic pain syndrome caused by compression and/or inflammation of spinal nerve roots by herniated disc material, and its treatment is therefore usually aimed at reducing compression and inflammation. Studies have shown that both systemic local anesthetics and N-methyl-D-aspartate (NMDA) receptor antagonists may produce analgesia in a variety of neuropathic pain syndromes. The present study evaluated the analgesic efficacy of i.v. infusions of the local anesthetic lidocaine, the NMDA receptor antagonist amantadine, and a placebo in sciatica.


METHODS
Thirty patients with sciatica, as confirmed by physical examination and imaging studies, were enrolled in a randomized, double-blind, three-arm crossover trial. Infusions of amantadine (2.5 mg/kg), lidocaine (5 mg/kg), and a placebo were administered over a 2-hour period, 2-7 days apart from each other. Spontaneous pain (visual analog scale) and evoked pain (straight leg raise) were measured every 30 minutes for 3 hours.


RESULTS
Lidocaine reduced spontaneous pain as compared with amantadine and with the placebo for all measurements and at a significant level at the 30 (P < .05), 120, and 180 (P < .01) minute time points. Maximal pain reduction from the baseline was 62 +/- 7% for lidocaine, 43 +/- 7% for amantadine, and 47 +/- 7% for the placebo. Straight leg raise test also significantly improved with lidocaine (from 30 to 37 degrees; P < .05), as compared to amantadine (34-36 degrees) and to the placebo (32-34 degrees). All three treatments were relatively well tolerated.


CONCLUSIONS
Intravenous lidocaine, rather than amantadine, reduces both spontaneous and evoked sciatic pain.
Medrik-Goldberg
T
T
Pain Relief Unit, Rambam Medical Center, Haifa, Israel.
Lifschitz
D
D
Pud
D
D
Adler
R
R
Eisenberg
E
E
D000293:Adolescent; D000328:Adult; D000547:Amantadine / Q000009:adverse effects / Q000627:therapeutic use*; D018712:Analgesics, Non-Narcotic / Q000009:adverse effects / Q000627:therapeutic use*; D000779:Anesthetics, Local / Q000009:adverse effects / Q000627:therapeutic use; D004311:Double-Blind Method; D004359:Drug Therapy, Combination; D005260:Female; D006801:Humans; D007275:Injections, Intravenous; D008012:Lidocaine / Q000009:adverse effects / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D012585:Sciatica / Q000188:drug therapy*
D018712:Analgesics, Non-Narcotic; D000779:Anesthetics, Local; D008012:Lidocaine; D000547:Amantadine