Adverse Drug Reactions Reported With Cholinesterase Inhibitors

Background: No worldwide pharmacovigilance study evaluating the spectrum of adverse drug reactions (ADRs) induced by cholinesterase inhibitors (ChEI) in Alzheimer’s disease has been conducted since their emergence on the market. Objective: To describe ChEI related ADRs in Alzheimer’s disease (donepezil, rivastigmine, and galantamine) and characterize their seriousness as reported by national pharmacovigilance systems to VigiBase, a World Health Organization International Drug Monitoring Program database, between 1998 and 2013. Methods: All ChEI related reports, submitted to VigiBase between 1998 and 2013 from the five continents were extracted. Analyses were carried out for general, serious, and nonserious ADRs. Results: A total of 18 955 reports (43 753 ADRs) from 58 countries were reported: 60.1% in women; mean age 77.4 ± 9.1 years. Most reports originated from Europe (47.6%) and North America (40.4%). Rivastigmine and donepezil were involved in most reports (41.4% each). The most frequently reported ADRs were neuropsychiatric (31.4%), gastrointestinal (15.9%), general (11.9%), and cardiovascular (11.7%) disorders. During the 2006-2013 period, serious ADRs remained more often reported than nonserious ones; the most serious were neuropsychiatric (34.0%), general (14.0%), cardiovascular (12.1%), and gastrointestinal (11.6%) disorders. Medication errors were reported in 2.0% of serious cases. Death occurred in 2.3% of the reports. Conclusions: This international pharmacovigilance study highlights the ADR pattern induced by ChEIs. Neuropsychiatric events were the most frequently reported ADRs. Serious cardiovascular events were frequently reported, suggesting that their significance has probably been previously underestimated. Given the frailty of the patients and the frequent comedications, caution is advised before introducing a ChEI.

Use of rivastigmine or galantamine and risk of adverse cardiac events: a database study from the Netherlands

BACKGROUND

Two cholinesterase inhibitors (ChEIs), rivastigmine and galantamine, are used to treat Alzheimer disease in the Netherlands. Several adverse cardiac events have been reported for these medications.

OBJECTIVE

We aimed to assess if the use of ChEIs increased the risk of cardiac events in the Netherlands.

METHODS

A cohort crossover study of the PHARMO Record Linking System database included patients who initiated ChEIs at age 50 years or older, had at least 1 dispensing of a ChEI drug between 1998 and 2008, a 1-year history in PHARMO, and 1 subsequent dispensing of any medication. Two outcomes were assessed: a first hospitalization for syncope or atrioventricular block. Poisson and Cox regression were used to calculate incidence densities and hazard ratios for cardiac events during periods with ChEI use, compared with periods without ChEI use.

RESULTS

During the complete observation period of 8.9 years (interquartile range 6.7 to 10.2) there were 132 first hospitalizations for atrioventricular block and 17 first hospitalizations for syncope among 3358 patients. The adjusted incidence densities were significantly increased during ChEI exposure for syncope and atrioventricular block, when compared with the background incidence densities in the roughly 5 years before the last year before ChEI initiation. However, when exposed periods were compared with the unexposed periods 1 year before ChEI initiation and times after exposure, the adjusted hazard ratios remained increased for syncope and atrioventricular block, but increases were not significant anymore.

CONCLUSIONS

Exposure to ChEIs might increase the risk of adverse cardiac events, but small numbers of cases limit conclusions about the risk in this population and research on larger study samples is needed.