Introduction: At present acetylcholinesterase inhibitors (AChEI) are used in the treatment of the cognitive deterioration associated with Alzheimer s disease (AD). The side effects of these drugs are linked with the increase in acetylcholine, which limits their effectiveness, and must be adjusted to the patient close to the maximum tolerated dose.
Patients and methods: We conducted a comparative retrospective study of the tolerance and the adverse events (AE) of two AChEI in a group of patients with very slight and mild probable AD over a 6 month period.
Results: The sample was made up of 175 patients, of which 134 began therapy with 5 10 mg/day of donepezil and 41 with 6 12 mg/day of rivastigmine. 20% of the patients presented AE and 8% abandoned the treatment. Gastrointestinal disorders (GID) were the main AE observed (57.1%). Only 6% of the patients treated with donepezil abandoned the therapy because of the AE as opposed to 14.6% of the patients treated with rivastigmine. Patients treated with rivastigmine displayed a higher incidence of GID and the relative risk of presenting GID was 4.4 times higher than in the patients treated with donepezil.
Conclusions: The GID associated to therapy with AChEI are the main reason for abandoning treatment and occur more frequently in patients treated with rivastigmine.