Which side effect is most commonly associated with the class of drugs that includes Galantamine, Donepezil, and Rivastigmine?

The most commonly associated side effect with the class of drugs that includes Galantamine, Donepezil, and Rivastigmine is gastrointestinal distress. These drugs are acetylcholinesterase inhibitors, which increase the levels of acetylcholine in the brain by preventing its breakdown. While this mechanism is beneficial for certain cognitive disorders, such as Alzheimer's disease, one consequence of increased acetylcholine activity is heightened gastrointestinal motility and secretions, leading to symptoms like nausea, vomiting, diarrhea, and overall gastrointestinal discomfort.

Patients taking these medications often report these side effects, especially when beginning treatment or when doses are increased. Other choices like joint pain, dry mouth, and unusual fatigue are less commonly linked to this class of drugs. Understanding the pharmacodynamics of cholinergic agents clarifies why gastrointestinal disturbances are a prominent issue with these medications.