2 yr old son has a constant cough due to runny nose drainage. anything avail to use to "dry him out" like sudafed does for me?

Not really: Most otc cough ; cold meds are not indicated for children under 4 years old- either because they don't really work or they have more side effects in younger children. Use saline nose drops and suction out his nose- as often as needed. Apply vaseline to the edges of his nose if irritated. Honey can be used for cough in kids over 1 yr old. If he's not better, see your pediatrician.