Prega belongs to a group of medicines used to treat epilepsy, neuropathic pain and generalized anxiety disorder (GAD) in adults. Peripheral and central neuropathic pain: Prega is used to treat long lasting pain caused by damage to the nerves. A variety of diseases can cause peripheral neuropathic pain, such as diabetes or shingles. Pain sensations may be described as hot, burning, throbbing, shooting, stabbing, sharp, cramping, aching, tingling, numbness, pins and needles. Peripheral and central neuropathic pain may also be associated with mood changes, sleep disturbance, fatigue (tiredness), and can have an impact on physical and social functioning and overall quality of life. Epilepsy: Prega is used to treat a certain form of epilepsy (partial seizures with or without secondary generalization) in adults. Your doctor will prescribe Prega for you to help treat your epilepsy when your current treatment is not controlling your condition. You should take Prega in addition to your current treatment. Prega is not intended to be used alone, but should always be used in combination with other anti-epileptic treatment. Generalized Anxiety Disorder: Prega is used to treat Generalized Anxiety Disorder (GAD). The symptoms of GAD are prolonged excessive anxiety and worry that are difficult to control. GAD can also cause restlessness or feeling keyed up or on edge, being easily fatigued (tired), having difficulty concentrating or mind going blank, feeling irritable, and having muscle tension or sleep disturbance. This is different to the stresses and strains of everyday life.