White tongue on back of my tongue.

Any rational opinion cannot be given without a clinical examination or at least a look at the clinical picture of your tongue. Please post one if possible. It is not mandatory to prescribe probiotics with antibiotics all the time, and also not every patient of long term antibiotic use will develop oral thrush. You can follow some simple conservative steps and observe. Clean your tongue using your toothbrush only after every time you brush your teeth and avoid the use of tongue cleaners for this purpose. Maintain a good level of hydration. You can take probiotics as they are good for general Physical health also. Please do not start antifungal therapy unless the diagnosis has been objectively established by a dentist. Regards