They have been found to have therapeutic efficacy in neuropathic pain states. These two agents have been largely replaced due to the introduction of many newer, better-tolerated, and safer antiepileptic drugs.
Many studies are ongoing to evaluate their efficacy in neuropathic pain states.
Initial dosing should be done at a low dose administered at bedtime, increased slowly up to a therapeutic level over 4 to 8 weeks. These medications do not have a ceiling dose, but are usually more effective at higher doses. Clinically the dose should be titrated upwards until side effects are encountered, then back down a small amount. The pain relief obtained is gradual with most agreeing that an adequate trial of an AED for pain should last 4-8 weeks at therapeutic doses prior to calling a medication ineffective. A brief summary of clinical uses, mechanism of action, and side effects will be presented for the following AEDs.