Hi.. Thanks for the query.. Well, Lisinopril and other blood pressure medications has a side effect of causing a dry mouth. Triamtterene Hctz too has a side effect of causing dry mouth.. So in your case dry mouth is clearly due to side effect of the medication that you are taking and each one is adding to dry mouth caused by the other.. Coughing can also be due to irritation in throat caused due to dryness which can induce a cough reflex.. So first thing that you need to do is to consult your treating Physician and get evaluated and explain him the side effects.. He can either change the drug combination or reduce the doses for improving the symptoms.. For symptomatic relief you can start stimulating saliva flow by chewing sugar free chewing gum and sucking lemon drops.. You can also instil methyl-cellulose containing artificial saliva drops to lubricate the mouth.. You should avoid using regular mouthwash as they have drying effect in mouth and can use special mouthwash like Biotene that help in relieving dry mouth.. Hope this information helps you.. Regards. Dr.Honey Arora.