The importance of monitoring adverse drug reactions in elderly patients: the results of a long-term pharmacovigilance programme.

OBJECTIVE: To recognise and prevent ADRs (including DDIs) in the elderly through a 4-year post-marketing active pharmacovigilance programme. The programme was designed to enhance high quality spontaneous reporting of ADRs in elderly patients by sampling the Italian population and was termed 'Pharmacovigilance in Geriatry (ViGer)'.

METHODS: ADRs were collected for adults aged over 65 years of age treated in nursing homes, continuing care retirement communities and territorial health services in Lombardy. ADRs were evaluated using the Adverse Drug Reaction Probability Scale (Naranjo) and analysed with respect to time, sex, category of ADR, seriousness, suspected medicines, notoriety. We analysed all the potential DDIs.

RESULTS: We detected 1073 cases reports corresponding to 2110 ADRs. Vaccines, antibacterials for systemic use and antineoplastic agents were the pharmacotherapeutic subgroups most frequently involved. 18% of ADRs reports were classified as serious. In 752 reports patients were described as in polytherapy; in 55 patients (7.3%) the reported ADR were probably preventable because of DDIs involvement.

CONCLUSION: The ViGer project demonstrated that active pos-marketing pharmacovigilance programmes are a valid strategy to increase awareness on geriatrics pharmacology, reduce underreporting and provide important information on previous unknown ADRs and DDIs, resulting in a therapy optimisation in clinical practice in the geriatric setting.