Abstract
Gabapentin is an important therapeutic agent used to treat intractable pain. We attempted to clarify whether the initial effect of gabapentin could predict the long-term outcome in patients with chronic pain (postherpetic neuralgia and/or spinal disease). We administered gabapentin to 507 outpatients diagnosed with postherpetic neuralgia (n=160), spinal diseases (n=167), or any other conditions including cancer and/or post-operative pain (n=180). Moreover, we evaluated the effectiveness of gabapentin for these chronic pain diseases. Gabapentin improved pain in 64% of patients during the initial period, and 67% during the long-term period.
We found that the long-term effect of gabapentin could be expected if the patients responded to gabapentin during the initial trial, however, gabapentin did not relieve pain in patients who showed little effect initially.
Adverse effects such as dizziness and somnolence were observed in around 25% of all patients, but none of these events were serious. From the present results, it may thus be possible to predict the long-term effect of gabapentin based on its initial analgesic effect in individual patients. Pharmacological treatment with gabapentin could be a good option for various painful conditions.
