What Causes Reduced Urination, Dry Mouth, Severe Anxiety And Memory Loss?

Hi , My Father - 76 years old, 6 feet height, 84 kg weight is prescribed QUTAN - 25 mg, daily one at evening 7 PM. He was prescribed this as he was having great anxiety that he is not urinating enough and that his toungue t always dry and he need to eat vitamin c consistent for this.After taking QUTAN-25 the above 2 issues are resolved , but he is having a memory lossnow and looks sedated throughout . He forget his my mom's name and our names etc but can remember his grandparets and aunts etc, is this an expected behaviour and will improve over time?