<prompt> Which drug is not used in Alzhermers diseaseTacrineGalantamineDonepezilRivastigmine  <response>: Ans. is a i.e., Tacrine o Recently 4 cholinergic activators cerebroselective anticholinesterase drugs are being approved by UK USA for use in AD Tacrine, Rivastigmine, Donepezil, Galantamine. o Because of hepatotoxicity, and requirement of frequent obsing, tacrine is less often used than other agents. 