The rationale and use of topiramate for treating neuropathic pain.
OBJECTIVE
To outline the modes of action of topiramate and to examine the theoretical reasons as to why topiramate may alleviate neuropathic pain. Results of animal and human studies in the use of topiramate for treating pain are reviewed, together with case studies describing situations where topiramate was effective when other treatments have failed.


CONCLUSIONS
Topiramate acts on neuronal transmission in at least five ways: by modulating voltage-gated sodium ion channels, potentiating gamma-aminobutyric acid inhibition, blocking excitatory glutamate neurotransmission, modulating voltage-gated calcium ion channels, and by inhibiting carbonic anhydrase. This review suggests that there are good theoretical reasons for a trial of topiramate in patients with neuropathic pain where conventional medical treatments have failed. Although not currently licensed for treating pain, topiramate should be considered before invasive methods of pain relief are contemplated. Most of the side effects of topiramate are dose dependent, but by starting medication with a low dose (</=25 mg/d) that is gradually titrated upward, tolerance is much more easily achieved.
Chong
M S
MS
The Medway Hospitals NHS Trust, Gillingham, United Kingdom. mschong@doctors.org.uk
Libretto
Susan E
SE
D000700:Analgesics / Q000494:pharmacology / Q000627:therapeutic use*; D000818:Animals; D002256:Carbonic Anhydrases; D002986:Clinical Trials as Topic; D004195:Disease Models, Animal; D004791:Enzyme Inhibitors; D005069:Evaluation Studies as Topic; D005632:Fructose / Q000031:analogs & derivatives* / Q000494:pharmacology / Q000627:therapeutic use*; D006801:Humans; D006930:Hyperalgesia; D007473:Ion Channels / Q000187:drug effects; D009437:Neuralgia / Q000188:drug therapy* / Q000378:metabolism / Q000503:physiopathology; D018079:Receptors, GABA / Q000187:drug effects; D017470:Receptors, Glutamate / Q000187:drug effects; D009435:Synaptic Transmission / Q000187:drug effects; D000077236:Topiramate
D000700:Analgesics; D004791:Enzyme Inhibitors; D007473:Ion Channels; D018079:Receptors, GABA; D017470:Receptors, Glutamate; D000077236:Topiramate; D005632:Fructose; D002256:Carbonic Anhydrases