To relieve dryness of the mouth caused by taking clonidine, the patient may suck sugar-free candies or chew sugar-free gum to kindle the flow of saliva. Both the gum and hard candies can stimulate the salivary glands to produce more saliva. Another way is to limit the intake of soda or coffee as they tend to make your mouth drier; besides, they are not good for hypertensive patients.