According to the dentists, people who have multiple medications suffer from dry mouth. This was proved in survey conducted in US by the the Academy of General Dentistry (AGD). 

Dry mouth, or xerostomia, is caused by a reduction in salivary function. It affects approximately one in four Americans, placing more than 25% of people at risk for tooth decay. 

"The number of xerostomia cases has increased greatly over time because people are taking more and more medications," said Cindy Kleinman, member, AGD. 

"General dentists are seeing this trend in their offices, which is why they are trying to learn all they can about this condition. The more they know, the better they will be at diagnosing and treating patients," she added. 

There are more than 400 prescription and non-prescription drugs associated with xerostomia, according to Raymond K. Martin, member AGD. 

"Anti-depressants, pain-killers, diuretics, antihistamines, tranquilisers and anti-hypersensitives can all contribute to dry mouth," said Martin. "People who take several of these medications are more susceptible." 

The most common symptoms reported by patients include constant thirst and difficulty eating, swallowing, or speaking. 

Foamy or stringy saliva, irritation of the tongue, burning of the tissues inside the mouth, painful ulcerations and dentin hypersensitivity (extreme sensitivity in one or more teeth) are also dry mouth symptoms.