title: What happens when donepezil is suddenly withdrawn? An open label trial in dementia with Lewy bodies and Parkinson's disease with dementia.
abstract: BACKGROUND
  This open label study was designed to assess the effects of donepezil treatment, its withdrawal and subsequent recommencement on cognitive functioning, behaviour and parkinsonian symptoms in patients with probable dementia with Lewy bodies (DLB) and with Parkinson's disease who subsequently developed dementia (PDD).
  
  
  METHODS
  Eight patients with DLB and 11 with PDD were treated with up to 10 mg of donepezil daily for 20 weeks followed by a 6-week withdrawal period. The primary outcome measures were the Mini-Mental State Examination (MMSE), the total Neuropsychiatric Inventory (NPI) and the Unified Parkinson's Disease Rating Scale III. Testing was conducted before dosing, at week 20, at a withdrawal visit and 3 months after recommencement on donepezil.
  
  
  RESULTS
  Patients with DLB and PDD showed a significant improvement in cognition with treatment, loss of this improvement on withdrawal and restoration of treatment gains on recommencement. Both groups also demonstrated favourable, behavioural changes with treatment, PDD patients in particular deteriorating significantly after withdrawal. The only NPI symptom domain that showed a consistent significant response to both treatment (positive) and withdrawal (negative) was hallucinations. The medication was well tolerated and parkinsonian features did not alter significantly over the testing sessions.
  
  
  CONCLUSIONS
  Our results suggest that treatment with donepezil improves cognition and hallucinations without increasing parkinsonian symptoms, and its sudden withdrawal is usually detrimental, producing acute cognitive and behavioural decline. Although recommencement on donepezil appears to reverse this deterioration we do not advise its abrupt discontinuation in this population.
authors: Institute for Ageing and Health, Wolfson Research Centre, Newcastle General Hospital, Newcastle upon Tyne, UK.
authors: Thaís S C
authors: TS
authors: Minett
authors: Alan
authors: A
authors: Thomas
authors: Lucy M
authors: LM
authors: Wilkinson
authors: Sarah L
authors: SL
authors: Daniel
authors: Jonathan
authors: J
authors: Sanders
authors: Jonathan
authors: J
authors: Richardson
authors: Elizabeth
authors: E
authors: Littlewood
authors: Pat
authors: P
authors: Myint
authors: Jane
authors: J
authors: Newby
authors: Ian G
authors: IG
authors: McKeith
mesh_terms: D002800:Cholinesterase Inhibitors / Q000009:adverse effects / Q000627:therapeutic use*; D003704:Dementia / Q000188:drug therapy / Q000209:etiology; D000077265:Donepezil; D004334:Drug Administration Schedule; D006801:Humans; D007189:Indans / Q000009:adverse effects / Q000627:therapeutic use*; D020961:Lewy Body Disease / Q000188:drug therapy*; D009483:Neuropsychological Tests; D018697:Nootropic Agents / Q000009:adverse effects / Q000627:therapeutic use*; D010300:Parkinson Disease / Q000188:drug therapy* / Q000523:psychology; D010880:Piperidines / Q000009:adverse effects / Q000627:therapeutic use*; D011569:Psychiatric Status Rating Scales; D016896:Treatment Outcome
chemical_list: D002800:Cholinesterase Inhibitors; D007189:Indans; D018697:Nootropic Agents; D010880:Piperidines; D000077265:Donepezil