Gabapentin and Donepezil Combination on Experimental Human Pain Models

This study will compare the effects of gabapentin alone, and gabapentin + donepezil given together in two types of experimental electrical pain tests in up to 48 healthy male subjects (after 24 recruited in the first cohort an interim analysis will be performed). The study is a randomized, double blind, placebo controlled, 3 was cross-over design study with incomplete block design and 4 treatment options. Placebo, gabapentin alone (lower dose and higher dose) or gabapentin (lower dose) with donepezil.