Nausea/vomiting and other gastrointestinal system disorders may cause severe nutritional complication in elderly neurologic patients.

To identify possible gastrointestinal side effects in patients receiving Alzheimer's disease treatment.

This research included 45 geriatric patients enrolled in a private long-term care institution with mean age of 88.38±0.84 years old, mean weight of en 60.28±2.00kg with Alzheimer's disease.

Drugs administered to patients with Alzheime's disease were: donepezil 0.16mg/kg/day, administered to 53.33% (24) of patients ; rivastigmine patch 9.50mg/day given to15.56%(7) of patients and galantamine 0.40mg/kg/day given to 4.44% (2) of patients.

26.67% (12) of subjects did not received any specific drug for Alzheimer's disease.

Nausea and vomiting were observed in 20,83% (5) patients who received donepezil, in 85.71% (6) from rivastigmine group and in 2 patients treated with galantamine.

Appetite loss was identified in 20,83% of patients receiving donepezil.

The increase of cholinergic activity induced by donepezil, rivastigmine and galantamine intensify cholinergic neurons inputs from chemoreceptor trigger zone, solitary tract nucleus and cerebellum to medullary emetic centre and thus may lead to emese stimulation in these patients.

Regarding the possibility of nausea/vomiting and appetite loss in patients receiving Alzheimer's disease cholinergic drugs, a more easily digestible meal should be considered for these patients.