Carbamazepine is effective in chronic neuropathic pain, with caveats. No trial was longer than four weeks, of good reporting quality, using outcomes equivalent to at least moderate clinical benefit. In these circumstances, caution is needed in interpretation, and meaningful comparison with other interventions is not possible.
The analgesic effect of tocainide in trigeminal neuralgia.
Tocainide is a derivative of lidocaine with anti-arrhythmic action and, unlike lidocaine, can be used for oral treatment. Tocainide was alternatively with carbamazepine given to 12 patients with trigeminal neuralgia in a double-blind cross-over study for 2 weeks. The analgesic effect was estimated each day by the patients using a 0-10-point scale summarizing the frequency and severity of the attacks. The similarity in analgesic effect of the two drugs was striking. A possible analgesic mechanism could be that tocainide blocks the sodium channels in the hyperexcitable nerve membranes in the pain-producing foci in trigeminal neuralgia.