Medications are often prescribed for off label use......I haven't taken Vimpat, but most of us have taken Neurontin (Gabapentin), Keppra, Dilantin, Valium,,Lumonal, Vitamin B6, Tegretol, Topamax, Lyrica, Lamictal,Vitamin E , Klonipin, Ativan, Diamox, Depakote, Savella
The list below are huge. Most epilepsy medications can be used for neuropathic pain & headaches. Many of the medications I listed are used for many diagnoses and symptoms. When a drug is developed and on the market for a while f it is found to help other medical issues.
I take Adderall XR for Depression because I can't take anti depressant.
Link from the FDA that gives the guideline for off label orphan drug use. "Orhpan Drugs" is the term used for medications for Rare Disorders: http://www.anthem.com/medicalpolicies/guidelines/gl_pw_a048553.htm
Seizure Drug list Links :
Neuropathy Drug List Links:
http://www.emedicinehealth.com/neuropathy/page9_em.htm#medication *** Really great Article that explains why different drug types are used***
Headache Medication lists:
http://www.rxlist.com/script/main/art.asp?articlekey=104593 Great Article that explains why different medication types are used.
I really hope this post and links help explain why certain Medications are used for multiple symptoms and illnesses.