some common drugs which cause drying of the mouth and may interfere with swallowing include the following:
 

analagesic mixtures
anticonvulsants
antiemitics
antihistamines
antihypertensives
antinauseants
antiparkinsonism agents
antispasmodic drugs
appetite suppressants
cold medications
decongestants
diurectics
expectorants
muscle relaxants
psychotrophic durgs (CNS depressants, tranquilizers, etc.)
sedatives