All of the cholinesterase inhibitors may cause such side effects as nausea, vomiting, loss of appetite, and increased frequency of bowel movements. Tacrine can also contribute to liver damage. For this reason, physicians prescribe this drug less frequently than the others. Donepezil is generally well tolerated by patients. In clinical trials, rivastigmine was also well tolerated, but because the drug only became available in mid-2000, little is known about how it will be tolerated in the general population.
Weight loss is known to occur in some patients taking rivastigmine.
Side effects can vary from one patient to the next, just as effectiveness will vary. For one individual, one drug may be more effective but have greater side effects. For another patient, the same drug may be less effective but have no side effects. More side effects may occur if two or more of the drugs are taken simultaneously. Questions for your physician Clear and thorough communication between the physician and the patient or caregiver is essential in making a decision about what drug to take.