Dr. Pritesh Patel

"Usually patients had been on donepezil for a number of years, and [were] declining," said Pritesh Patel, MD, a fellow at Jersey Shore University Medical Center, Neptune, New Jersey, affiliated with Robert Wood Johnson Medical School.Dr. Patel said the impetus for switching usually comes from family members or when patients change facilities and formularies change.

Side effects of donepezil -- primarily gastrointestinal (GI) -- usually subside, but can reactivate if the patient has a change in condition, Dr. Patel said.Both agents are anticholinergics, with galantamine acting on the nicotinic as well as muscarinic sites."A lot of patients don't tolerate [either of] these medications," he said, so both have to be titrated up carefully.

New drugs acting through glutamate transmission are in the pipeline or already approved, and these give "almost no nausea or GI side effects," Dr. Patel said.