Multiple dose gabapentin attenuates cutaneous pain and central sensitisation but

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Pain. 2006 Jun 13

Multiple dose gabapentin attenuates cutaneous pain and central

sensitisation but not muscle pain in healthy volunteers.

Segerdahl M.

Department for Clinical Science, Intervention and Technology,

Division for Anesthesiology, Karolinska Institutet, Karolinska

University Hospital, Huddinge, S-141 86 Stockholm, Sweden.

Various muscle pains constitute a large clinical problem, both for

patients and clinicians. Gabapentin is an established therapy in

neuropathic pain and reduces cutaneous pain in healthy volunteers.

Gabapentin in combination with other analgesics reduces post-

operative pain. No data exist on the effect of gabapentin on muscle

pain.

This study investigates the effect of gabapentin on muscle and

cutaneous pain in healthy volunteers. Sixteen healthy volunteers, 8

male/8 female, were included in this double-blind three-session

crossover study comparing the effects of 0, 1200, 1800 and 2600mg

(pre-treatment, titrated over 4 doses) gabapentin and placebo. Muscle

pain was induced by infusing 0.5ml of hypertonic saline into the

anterior tibial muscle. Simultaneously, subjects graded pain on a

computerized visual analog scale (VAS, 0-10). Total (AUC,

VAS*duration in s) and maximal pain (VAS(max)) were assessed. Areas

of local and referred pain were measured. Further, continuous

intracutaneous electrical stimulation was applied to the forearm.

Current was increased until pain intensity 5/10 or until subjects

reached a cut-off of 70mA. Spontaneous pain (VAS 0-10), areas of

secondary hyperalgesia to pinprick (cm(2)) and mechanical pain

threshold (g) within this area were assessed.

Gabapentin pre-treatment reduced sensitivity to electrical induction

of skin pain by 14%, p=0.016. Secondary hyperalgesia was induced, but

areas were reduced after pre-treatment, p<0.05. Mechanical pain

thresholds were unaffected. Pain induced by intramuscular infusion of

hypertonic saline was not affected by gabapentin.

In conclusion, single or repeated dosing of gabapentin reduced

cutaneous but not muscle pain in healthy volunteers.