Abstracts

Pregabalin is an alpha-2-delta ligand that in clinical trials has been demonstrated to be efficacious as adjunct treatment for partial seizures with/without secondary generalizations. In addition to its anticonvulsant properties, pregabalin has also been found to exhibit analgesic and anxiolytic characteristics. Data from 5 DPN, 4 PHN, and 1 DPN/PHN clinical trials are presented to characterize the analgesic properties exhibited by pregabalin. Pregabalin[apos]s ability to reduce neuropathic pain in DPN or PHN patients was assessed using data from 5 DPN, 4 PHN, and 1 DPN/PHN placebo-controlled trials involving 2331 patients (1336 had DPN and 995 had PHN). Three pregabalin doses were studied: 150, 300, and 600 mg/day delivered either twice- or three-times daily. In all trials, the primary efficacy measure was mean end-point pain score derived from patient-recorded daily-pain diaries (11-point scale; 0=no pain; 10=worst possible pain). Efficacy was also assessed by measuring the proportion of patients reporting pain reductions of [ge]30% and [ge]50%. DPN and PHN patients treated with pregabalin consistently reported significantly greater pain reductions than placebo (PBO) patients. At end-point, DPN patients receiving pregabalin 150, 300, and 600mg/day reported pain score reductions of [ndash]2.0, [ndash]2.3, and [ndash]2.7 vs [ndash]1.5 for patients receiving PBO (P[le]0.007). Similarly, at end-point, PHN patients receiving pregabalin 150, 300, and 600 mg/day experienced pain score reductions of [ndash]1.6, [ndash]2.2, and [ndash]2.7 vs [ndash]0.9 for patients receiving PBO (P[le]0.0001). Pain reductions were positively correlated with dose. 43%, 55%, and 62% of DPN patients receiving pregabalin 150, 300, and 600mg/day reported pain reductions [ge]30% (a reduction level found to be clinically meaningful) while only 37% of DPN patients on PBO reported similar reductions. When treatments were compared by the number of patients reporting pain reductions [ge]50%, the analysis revealed that 27%, 39%, and 46% of DPN patients on pregabalin 150, 300, and 600mg/day reported reductions [ge]50% compared to only 22% of DPN patients on PBO. Similar analyses performed on PHN patients revealed that 37%, 47%, and 60% of PHN patients receiving pregabalin 150, 300, and 600mg/day reported pain reductions [ge]30% vs 22% of PHN patients on PBO; 25%, 29%, and 47% of PHN patients on pregabalin 150, 300, and 600mg/day reported reductions [ge]50% vs 14% of PHN patients on PBO. AEs were generally mild to moderate in intensity (dizziness and somnolence were the most common) and led to discontinuation in 11% and 4% of pregabalin and PBO patients. Pregabalin was generally well tolerated; significant and clinically meaningful reductions in pain ([ge]30%) were demonstrated in up to 62% of DPN and 60% of PHN patients. (Supported by Pfizer Inc.)