Adverse drug reactions in elderly: a five-year review of spontaneous reports to the Portuguese pharmacovigilance system

ABSTRACT

Background: Adverse drug reactions (ADRs) are responsible for considerable morbidity and mortality in elderly. This study aimed to characterize the ADRs profile in Portuguese elderly patients, thus enhancing ADRs knowledge in this vulnerable population.

Methods: All spontaneous ADRs reported to the Portuguese Pharmacovigilance System from 2013 to 2017 were examined. However, considering the aim of this study, ADRs referring to patients aged 65 and over were analyzed in higher detail and compared with those reported in non-elderly adults.

Results: Considering the age of 65 years and above, 3692 spontaneous reports of suspected ADRs were analyzed. The suspected ADRs most frequently reported fall within the categories of general disorders and administration site conditions, and skin and subcutaneous tissue complaints. Regarding therapeutic agents, the antineoplastic drugs were the most common involved. Among the 2458 cases of serious ADRs reported, 34.0% led to hospitalization and in 5.8% of them occurred a fatal outcome. The antineoplastic and antithrombotic drugs were the most represented pharmacotherapeutic groups of suspected drugs involved in patient’s death (25.0% and 13.6%, respectively).

Conclusions: Most of the suspected ADRs were classified as serious. The majority of them were expected, so preventable, highlighting the importance of improving medication use in elderly.

KEYWORDS:

• Adverse drug reactions
• elderly
• pharmacovigilance
• pharmacovigilance system

6. Expert opinion

Adverse drug reactions (ADRs) are frequent and some of them can be serious. They are responsible for considerable morbidity and mortality in the elderly and lead to multiple admissions to the emergency rooms and acute hospitalizations. However, many ADRs reported as serious are preventable. Therefore, the accurate identification of ADRs, especially the early detection of those that are preventable, is an important key point for improving drug safety in elderly, thus increasing their quality of life. In addition, it is important to report all ADRs, as this enables the authorities to assess the presence of possible safety signals in this vulnerable population.

Article highlights

• Most of the suspected ADRs were reported as serious and preventable.

• Antineoplastic and antithrombotic agents were the suspected drugs most associated with a fatal outcome.

• Accurate identification of ADRs, especially the detection of preventable ADRs, is an important starting point to improve drug safety in elderly.

• Half of the unexpected ADRs were considered as probably being related to the suspected drug.

• It is important to report all ADRs in elderly to enable the assessment of possible safety signals in this special subpopulation.

Acknowledgments

The data presented in this work belong to the Portuguese Pharmacovigilance System. The authors would like to thank the Directorate of Risk Management for Medicines, National Authority of Medicines and Health Products, I.P. (INFARMED), Lisboa, Portugal.

Author contributions

C. Monteiro collected the data, organised the results and wrote the draft of the manuscript. A.P. Duarte and G. Alves supervised writing of the manuscript and revised it critically for intellectual content. All authors made substantial contributions and approved the final version of the manuscript.

Declaration of interest

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

Reviewer disclosures

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose

Additional information

Funding

This work was partially supported by INFARMED – National Authority of Medicines and Health Products, I.P. through the Pharmacovigilance Unit of Beira Interior and by CICS-UBI that is financed by National Funds from Fundação para a Ciência e a Tecnologia (FCT) and Community Funds [UIDB/00709/2020].