Substitution of gabapentin therapy with pregabalin therapy in neuropathic pain due to peripheral neuropathy.

OBJECTIVE

To determine the utility of substitution of pregabalin (PGB) for gabapentin (GBP) therapy in the relief of neuropathic pain (NeP) in patients with peripheral neuropathy (PN).

DESIGN

A cohort study was performed examining PGB substitution in patients who were GBP responders (> or =30% NeP relief on a visual analog scale [VAS]) or GBP nonresponders after prolonged GBP use, with further comparison to patients receiving continuous GBP therapy.

SETTING

Patients with PN and related NeP requiring GBP therapy were evaluated in a tertiary care neurological clinic at 0, 6, and 12 months.

OUTCOME MEASURES

Pain severity (Visual Analog Score [VAS]) was the primary outcome measure, while quality of life (European Quality of Life - 5 Domains [EQ-5D] and EQ-5D VAS) and occurrence of adverse events were secondary outcome measures.

RESULTS

Both GBP responder and nonresponder groups had additional NeP relief of about 25% following substitution of PGB after 6 and 12 months, while improved EQ-5D VAS was identified in the GBP nonresponder group. There were no serious adverse events for either medication, while GBP nonresponders discontinued PGB in more than 30% of cases due to inefficacy or adverse events.

CONCLUSIONS

Randomized, controlled, blinded head-to-head studies of GBP and PGB have not been published. The results of this open-label assessment of PGB substitution for GBP suggest that PGB may provide additional pain relief and possible improvement in quality of life above that received by GBP use in patients with NeP due to PN.