Pregabalin is effective in several neuropathic pain syndromes. This trial evaluated its efficacy, safety, and tolerability for treatment of painful HIV-associated neuropathy.
This randomized, double-blind, placebo-controlled, parallel-group trial included a 2-week double-blind dose-adjustment (150–600 mg/day BID) phase, a 12-week double-blind maintenance phase, and an optional 3-month open label extension phase. The primary efficacy measure was the mean Numeric Pain Rating Scale (NPRS) score, an 11-point numeric rating scale. Secondary measures included Patient Global Impression of Change (PGIC) and sleep measurements.
Baseline mean NPRS score was 6.93 for patients randomized to pregabalin (n = 151) and 6.72 for those to placebo (n = 151). Pregabalin average daily dosage (SD) was 385.7 (160.3) mg/d. At endpoint, pregabalin and placebo showed substantial reductions in mean NPRS score from baseline: −2.88 vs −2.63, p = 0.3941. Pregabalin had greater improvements in NPRS score relative to placebo at weeks 1 (−1.14 vs −0.69, p = 0.0131) and 2 (−1.92 vs −1.43, p = 0.0393), and at weeks 7 (−3.22 vs −2.53 p = 0.0307) and 8 (−3.33 vs −2.53, p = 0.0156). At all other time points, differences between groups were not significant. Sleep measurements and 7-item PGIC did not differ among treatment groups; however, collapsed PGIC scores showed 82.8% of pregabalin and 66.7% of placebo patients rated themselves in 1 of the 3 “improved” categories (p = 0.0077). Somnolence and dizziness were the most common adverse events with pregabalin.
Pregabalin was well-tolerated, but not superior to placebo in the treatment of painful HIV neuropathy. Factors predicting analgesic response in HIV neuropathy warrant additional research.
Classification of Evidence:
This Class II trial showed that pregabalin is not more effective than placebo in treatment of painful HIV neuropathy.
|AE||= adverse events;|
|ANCOVA||= analysis of covariance;|
|ARF||= activity region finder;|
|GPS||= Gracely Pain Scale;|
|HADS||= Hospital Anxiety and Depression Scale;|
|HIV-DSP||= HIV-associated distal sensory polyneuropathy;|
|LOCF||= last observation carried forward;|
|mBPI-sf||= modified Brief Pain Inventory–short form;|
|NPRS||= Numeric Pain Rating Scale;|
|NPSI||= Neuropathic Pain Symptom Inventory;|
|NRS||= Numeric Rating Scale;|
|PGIC||= Patient Global Impression of Change;|
|VAS||= visual analog scale.|