<prompt> Drug used in Alzheimers disease except:RivastigmineMemantineDonapezilClonidine  <response>: Ans: D Clonidine Ref: Synopsis of Psychiatry, Kaplan Sadock, 10th edition.p.343.Expanation:Alzheimers disease dementia is the most common type of dementia across the globe In India. Vascular dementia is MC.Dementia is a chronic, progressive condition characterized by:Decline in memory Short termExecutive dysfunction Agnosia. Aphasia and Apraxia.While many are irreversible, some have reversible causes- alcohol, head injury, deficiency states, metabolic and endocrinopathies.Alzheimers dementia is due to progressive loss of neurons starting from basal nucleus of Meynert which in turn due to accumulation of neurofibrillary tangles intracellular tau proteins amyloid plaques extracellular Bamyloid deposition.Since basal nucleus is the main place in brain where acetylcholine is synthesized Ach is responsible for transferring immediate memory into short term memory, decline of memory is seen.Recently, aluminum has been implicated for Alzheimers disease.Cortical dementiaSub-cortical dementiaMemory loss is early Aohassa is pronounced e.g., Alzheimers dementiaMood motor symptoms first Memory disturbance is late e.g., Parkinson. Lewy body diseaseThe aim of treatment of Alzheimers disease is preservation of existing cholinergic neurons or at least Ach by preventing its degradation - which in turn done by inhibition of Ach-estrase.The drugs used:1. Ach precursors- Choline. Lecithine2. AchE inhibitors- Donapezil. Rivastigmine, Galantamine DRG3. Antiglutamates - Memantine4. New drugs - Selegefine MAOI-B type, Ondensetron, Estrogen. NSAlDs.Clonidine is a central sympatholytic a, used to treat essential hypertension, diabetic neuropathy, Opioid withdrawal, menopausal symptoms hot flushes. 