Nervigesic Capsules 150 mg of pregabalin, an anticonvulsant widely used to treat neuropathic pain from diabetes, shingles, spinal cord injury, fibromyalgia, partial-onset seizures, and anxiety. It calms overactive nerves to ease pain and prevent seizures. Usually taken once or twice daily, effects may begin within a week. Common side effects include drowsiness, dizziness, weight gain, and blurred vision.