Modification and duration of pharmacological therapy for cognitive impairment in dementia

Within 1 month of starting an acetylcholinesterase inhibitor or memantine for dementia, assess the patient for adverse drug effects and adjust the dose or treatment accordingly; see also Guide to modifying pharmacological therapy for cognitive impairment in dementia. Within 6 months (usually after 2 to 3 months of therapy at the maximum tolerated dose), and thereafter every 6 months:

assess whether the patient has a clinically meaningful response to therapy—assess cognition, function and behaviour
monitor for adverse effects
discuss whether continuing treatment aligns with the patient’s goals and preferences.

Guide to modifying pharmacological therapy for cognitive impairment in dementia provides guidance on whether to maintain or adjust therapy.

If the patient tolerates and appears to benefit from an acetylcholinesterase inhibitor or memantine, continue it for as long as quality of life is maintained—that is, until the patient has end-stage dementia (eg lost independent mobility, can no longer swallow) and therapy is no longer achieving their goals and preferences.

For advice on stopping an acetylcholinesterase inhibitor or memantine, see here. Stopping these drugs can cause an irreversible or more rapid decline in function and cognition, and precipitate severe behavioural or psychological symptoms. However, this does not preclude stopping treatment at the request of the patient or their substitute decision-maker.

Table 1. Guide to modifying pharmacological therapy for cognitive impairment in dementia
[NB1]
Concern prompting modification	Modification of acetylcholinesterase inhibitor therapy	Modification of memantine therapy
intolerable adverse effects at lowest possible dosage	if used for: up to 12 months: switch or stop [NB2] longer than 12 months: stop [NB2]	stop
cognition and function have not improved or stabilised after using the maximum tolerated dose for at least 6 months	if used for: between 6 and 12 months: switch or stop [NB2] longer than 12 months: stop [NB2]	stop
after initial benefit, cognition and/or function significantly worsen over 6 months while using the maximum-tolerated dose	if used for: between 6 and 12 months: switch or stop [NB2] longer than 12 months: stop [NB2]	stop
patient or their substitute decision-maker decides to stop current therapy	stop [NB2]	stop
patient cannot take drug (eg can no longer swallow)	stop	stop
end-stage dementia (eg inability to respond to their environment)	stop	stop
nondementia life-limiting illness [NB3]	consider stopping	consider stopping
Note: NB1: Discuss treatment approach with the patient or their substitute decision-maker before adjusting therapy. NB2: Consider whether memantine is a suitable alternative to the acetylcholinesterase inhibitor; see Pharmacological therapy for cognitive impairment in Alzheimer dementia or Pharmacological therapy for cognitive impairment in dementia with Lewy bodies for guidance. NB3: See also Rationalising acetylcholinesterase inhibitors and memantine in palliative care.