Safety, tolerability, and efficacy of gabapentin in neuropathic pain: Results of a post-marketing surveillance study in 1214 Filipino patients

A post-marketing surveillance study of gabapentin usage in Filipino patients with neuropathic pain was conducted. Safety, tolerability and analgesic efficacy were assessed after a minimum of two weeks of gabapentin treatment, with starting and final doses determined by the prescribing physician. Of the 1,214 patients who entered the study, 95.7% completed the minimum two weeks duration of therapy. The mean age was 54 years, and the most common neuropathic pain diagnoses were painful diabetic neuropathy (30.4%), nonspecific neuropathies (20.2%), trigeminal neuralgia (12.8%), central pain after stroke (8.8%), and post-herpetic neuralgia (8.4%). Ninety-two percent of patients were maintained within a dose range of 300mg/day to 1200mg/day. The incidence of adverse events was 6%, and consisted mostly of somnolence and dizziness, with 76% of patients reporting “very good” to “excellent” tolerability. There were 34 documented dropouts (2.9%), of which only seven (0.6%) were thought to be related to an adverse event from gabapentin. Visual analog scale pain scores declined significantly from a mean of 67.8 + 20 mm at baseline, to 16.1 + 15mm after treatment (p< 0.05). In conclusion, gabapentin at 300mg/d to 1200mg/d is well tolerated and efficacious among Filipino patients with various neuropathic pain syndromes. INTRODUCTION