There is described a method for increasing the maximal tolerated close and thus the efficacy of an acetyl choline esterase inhibitor (AChEI) in a patient suffering from an Alzheimer type dementia by decreasing concomitant adverse effects by administration of said AChEI in combination with a non-anticholinergic antiemetic agent, whereby an enhanced acetyl choline esterase inhibition in the CNS of said patient is achieved and alleviation of the symptoms of Alzheimer type dementia in said patient is thereby improved to a greater extent. The use of a non-anticholinergic antiemetic agent for the preparation of a pharmaceutical composition for the treatment of Alzheimer type dementia in combination with an acetyl choline esterase inhibitor (AChEI) and pharmaceutical compositions comprising (a) a 5HT3 receptor antagonist, a dopamine antagonist, a H1-receptor antagonist, a cannabinoid agonist, aprepitant or casopitant as an antiemetic agent and (b) an acetylcholine esterase inhibitor are also described.