A sustained release formulation of carbamazepine (Tegretol XR) has been released recently in the United States, and is now available at your corner drug store. Although carbamazepine has been available for many years, this new formulation represents an improvement for dosing of this medication. In the past, it was necessary for most people to take carbamazepine 3 or 4 times a day. The new sustained-release preparation allows carbamazepine to be given twice a day. This will especially benefit persons who have difficulties with taking their medications more than a few times per day. The seizure types for which it is useful remain the same as regular carbamazepine. Thus, it is effective against partial onset seizures (focal, psychomotor, etc.) and tonic-clonic seizures.Finally, for person who have large fluctuations of their blood levels during the day, the sustained release formulation may allow for smoother levels and reduce side-effects. The new formulation is equivalent to the old medication on a mg per mg basis. Therefore, a person who takes 1200 mg per day of the regular formulation would now take 600 mg of the sustained release formulation twice a day.