To evaluate the effect of
tiagabine hydrochloride in
painful neuropathy in a pilot, open-label study.
Painful neuropathy is characterized by preferential involvement of small sensory and autonomic fibers.
Tiagabine increases
gamma-aminobutyric acid and might enhance the central
pain-control mechanisms. Seventeen patients (10 men, 7 women; mean age 51.4 +/- 7.7 y) with chronic
painful neuropathy (>6 months) were enrolled in this study. Week 0: All
pain medications were discontinued. Weeks 1-4: Dose of
tiagabine was increased weekly by 4 mg orally up to 16 mg in week 4. Quantitative sensory testing for vibration, cooling, and heat-
pain, and quantitative sudomotor axon reflex test (QSART) were done at week 0 and week 4. The McGill
Pain Questionnaire was administered weekly. Nine patients completed the study; 8 patients discontinued the treatment. Baseline
pain intensity was 6.2 +/- 3.1 on the McGill
Pain Questionnaire scale (0-10 range). Low doses (4-8 mg) of
tiagabine reduced
pain symptoms by 16-38%, improving surface
pain (37.5%), skin sensitivity (32.8%), burning (38.6%), cold (25.4%) and
pain sharpness (29%; p <0.03). Dull and deep
pain did not improve. Quantitative sensory testing abnormalities diminished with treatment (p <0.02). Autonomic test results did not change. This pilot study evaluated the potential of
tiagabine hydrochloride (
Gabitril) in treatment of painful sensory neuropathy.
Pain symptoms and quantitative sensory test results improved with treatment, especially at low doses of
tiagabine (4-8 mg). Higher doses (12-16 mg) were associated with increased number of adverse events.
Tiagabine may have potential benefits for treatment of
painful neuropathy; however, assessment of its efficacy in a larger study is needed.