Brief Answer: Unlikely ADR Detailed Answer: Hello, Thanks for choosing health care magic for posting your query. I have gone through your question in detail and I can understand what you are going through. Donepezil is a good drug for dementia. The problem that you are facing of legs bending at knees and not being able to stand up and foggyness in the morning are not some commonly reported adverse drug reactions of donepezil. But the fact that you noticed the same after starting the drug suggests that it is still possible. It would be wise to change the medicine in that case. The other options of dementia are memantin and rivastigmine. Both of them are good and in my clinical practice I use a lot of memantin. It is started in the dose of 5 mg and every week increased by 5 mg more to reach a dose of 20mg. Its effective in mild, moderate and severe dementia as well. You should not stop taking donepezil immediately. You should consult your neurologist/psychiatrist who can taper off the donepezil gradually and meanwhile start the upward titration of memantin as well. Hope I am able to answer your concerns. If you have any further query, I would be glad to help you. If not, you may close the discussion and if possible you may rate the answer for me, so that I get a good feedback. In future if you wish to contact me directly, you can use the below mentioned link: bit.ly/dr-srikanth-reddy Wish you good health, Kind regards Dr. Srikanth Reddy M.D.

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