A method for treating the adverse effects of acetyl-cholinesterase inhibitors used in the treatment of cognitive disorders such as acute delirium and cognitive impairment in elderly human patients. The administration of a clinically effective amount of a quaternary ammonium anti-cholinergic muscarinic receptor antagonist having very low lipid solubility substantially eliminates the adverse effects of urinary and/or fecal incontinence, nausea, bradycardia, bronchorrhea or brochospasm caused by the acetyl-cholinesterase inhibitors, without affecting the beneficial activity of the acetyl-cholinesterase inhibitors. This permits the administration of the optimum effective dosing of acetyl-cholinesterase inhibitors to provide maximum benefit to the patient with the added benefit of reducing or eliminating the unwanted side effects of fecal and urinary incontinence. Further, the combination of rivastigmine and glycopyrrolate has been effective in significantly improving cognitive function in patients suffering from acute dementia or cognitive impairment.
