He's had dementia/Alz for 13 years per doctors. His attitude and health has changed over the past 60 days. He started taking the Namenda XR about 2 months ago. I wonder if this new drug is causing this change. He developed a congestion that doctor says is not in his chest, but mainly in his throat area. He's taken Tussin and codine cough syrups and a week of antibiotics. Chest xrays show no problems in his lungs. These meds don't make a change in his congested cough. He's weaker, needs assistance walking now. He was always involved in the activities provided but now he's not interested. The sudden change scares me. The caregivers can't give me any advise on what to do.