Hi.. Can understand your concern... As per your complain chalky and gritty feeling in mouth is due to Dry mouth which can be due to a number of conditions like taking certain medication, fungal infection like Thrush, salivary gland disorders, nerve damage, chemotherapy and radiology etc.. In your case it seems to be due to medication more specifically taken to reduce blood pressure.. I would suggest you to consult your physician so that he can either change the medication or reduce the dose.. You can take Saliva substitute containing methyl cellulose that can be instilled in mouth so as to lubricate the mouth.. Saliva stimulants like sour candies, lemon drps or sugar free chewing gums can help in stimulating saliva flow.. Pilocarpine drug can be taken as it stimulate the salivary glands to increase saliva flow.. Drink plenty of water to maintain hydration.. Hope this information helps.. Thanks and regards.. Dr.Honey Nandwani Arora..