Case Series: Synergistic Effect of Gabapentin and Adjuvant Pregabalin in Neuropathic Pain.

Gabapentin and pregabalin both exert high affinity to the α2δ subunit of the voltage-gated calcium channels which inhibits excitatory neurotransmitter release. The synergistic mechanism was described in rats given combinations of gabapentin and pregabalin. In this case series, we described 2 cases which may illustrate the synergistic effect of gabapentin and pregabalin in treatment resistant neuropathic pain. Low dose pregabalin was added to therapeutic gabapentin to achieve appreciable pain reduction in one case and improved quality of life in another case. Further research with more enrollment and longer study duration may help elucidate the appropriate dosing and potential associated side effects.