Gabapin 400 mg is a treatment for adults with postherpetic neuralgia. The condition has a direct impact on nerve fibres and skin, causing painful blistering skin rash burning pain that is persistent after the rash disappear. It is also useful as adjunctive therapy in the treatment of partial seizures with and without secondary generalization in adults and paediatrics aged three years and older. The medicine is not effective for those who are allergic to gabapentin or other inactive ingredients of the medicine.