Drug companies come out with new versions of their medications just before the patent on the existing version expires, but Seroquel's patent does not expire until 2011. Israel's Teva Pharmaceuticals filed an FDA request to produce a generic version of quetiapine last year and they were promptly sued by AstraZenica. Was this a factor in the early request for a sustained-release version?
A sustained release version of quetiapine may be a good thing for patients. It's easier to take a medication once a day than twice a day - and a sustained release version may insure a more steady blood level of the medication. Risperdal (risperidone) is actually available in a version that can be given every two weeks - by injection. Patients who can't afford the new formulation of Seroquel (if it is approved) may save money by continuing to take the current version twice a day. They will certainly save money once a generic quetiapine is available.