Hi, Welcome to health care magic, Navidoxine is combination of two drugs, pyridoxine and Meclizine . Meclizine comes in category B according to FDA. it means that in Animal studies, researcher have found some congenital malformations, but in human beings, they have not seen. It means that we may use it if its benefits outweigh the risk. Pyridoxine is very good to prevent nausea in small doses that is 25 mg, maximum three times in a day. In higher doses it can cause peripheral neuropathy. So, if your Nausea is such that you are unable to eat anything, then you may take it at bed time. I hope that you have received proper advise about diet changes, and you are getting proper emotional support. Diet, you should take small, and frequent meals. Avoid fatty meals.Take food rich in carbohydrate and protein. Ginger, and lemonade, helps in relieving Nausea. If your Nausea does not get better, and if you start vomit more often, then instead of increasing the dose of Navidoxine, you should try Phenargan or medrol. But please do not forget to consult your Doctor, before you make any change. Enjoy pregnancy.