Newer antiepileptic drugs: possible uses in the treatment of neuropathic pain and migraine.
BACKGROUND
Both neuropathic pain and migraine are now being treated with a variety of newer antiepileptic drugs (AEDs). The proven efficacy of gabapentin in postherpetic neuralgia (PHN) and painful diabetic neuropathy (PDN), and of divalproex sodium in the prevention of migraine has led to increased clinical investigation of the newer AEDs for these conditions. While basic and clinical research are expanding the knowledge base concerning the fundamental mechanisms of neuropathic pain and migraine, growing recognition of the similarities in the pathophysiology of epilepsy, migraine, and various chronic pain disorders has further heightened interest in exploring the newer AEDs in the treatment of these conditions.


OBJECTIVE
The goals of this article were to review the empiric basis and scientific rationale for the use of AEDs in the treatment of neuropathic pain and migraine; summarize available clinical research on the use of 5 newer AEDs (gabapentin, lamotrigine, oxcarbazepine, topiramate, and zonisamide) in these conditions; and provide a summary comparison of the dosing, tolerability, and drug-interaction potential of these agents.


METHODS
Relevant English-language articles were identified through searches of MEDLINE (1990-March 2003), American Academy of Neurology abstracts (1999-2003), and American Epilepsy Society abstracts (2000-2002). The search terms were antiepileptic medication or drug, migraine headache, neuropathic pain, pathophysiology, treatment, mechanism of action, gabapentin, lamotrigine, oxcarbazepine, topiramate, and zonisamide.


CONCLUSIONS
The newer AEDs possess the potential advantages of better tolerability and fewer drug-drug interactions compared with standard treatments such as tricyclic antidepressants or established AEDs. However, with the exception of data supporting the efficacy of gabapentin in PHS and PDN, there is currently insufficient evidence to determine whether the newer AEDs have equal or superior efficacy relative to proven pharmacotherapies.
Pappagallo
Marco
M
Division of Chronic Pain, Department of Pain and Palliative Medicine, Beth Israel Medical Center, 1st Avenue at 16th Street, New York, NY 10003, USA. mpappaga@chpnet.org
D000927:Anticonvulsants / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D002986:Clinical Trials as Topic; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D006801:Humans; D008881:Migraine Disorders / Q000188:drug therapy* / Q000209:etiology / Q000517:prevention & control; D010146:Pain / Q000188:drug therapy* / Q000209:etiology; D010523:Peripheral Nervous System Diseases / Q000188:drug therapy* / Q000503:physiopathology
D000927:Anticonvulsants