Hi Sublime, Zanaflex is actually an old drug, The name is new but it's an older BP med. It's normally prescribed for spacticity rather than muscle spasm. As far as helping with nerve pain, It may help in the same way that Clonodine helps but it's not an anti seizure med like Neurontin, Topamax or Lamictyl.

I'm not sure why your doc would say it's for nerve pain other than the sedating effects may relax you and therefore give you some type of relief. Be careful driving untill your know how the med effects you. I used to use it as my last dose of muscle relaxer of the day to try to promote better sleep, But it didn't work on spasm as well as Soma and I don't think anythng other then genral anesthesia could keep me asleep a full night.LOL

Good luck, if you have spacticity or spasms, your more likely to see relief in those areas than from Neuropathic pain. Muscle spasm can stretch or squeeze nerves that passs though them so relieving spasm or spacticity may relieve some nerve pain from that effect. The sciatic nerve passes through the Glute minimus and maximus and periformis, so relieving one of those muscle spasms could certainly relief pressure being put on the nerves that pass through those muscle groups. So you may get some relief but your docs explanation of the mechanism of action isn't how the med may work. However your not the first patient to be prescribed a med, for off label use and with little explanation of how or why it may help.
Take care, Dave