Acetylcholinesterase inhibitors, also often called cholinesterase inhibitors, prevent the breaking down of acetylcholine (a substance located in the brain, which helps the communication of nerve cells with each other) by the enzyme acetylcholinesterase .
Donepezil (otherwise known as Aricept) , galantine (Reminyl), and rivastigmine (Exelon) are used in the treatment of the symptoms of dementia with Lewy bodies  and for mixed dementia diagnosis of Alzheimer’s disease.
Side effects include loss of appetite and nausea. Which usually gets better after two weeks of having the medication.
Antidepressants, most especially selective serotonin reuptake inhibitors (SSRIs) , might help in improving low mood and irritability.