Comorbidity, Polytherapy, and Drug Interactions in a Neurological Context: An Example of a Multidisciplinary Approach to Promote the Rational Use of Drugs

Purpose: A high number of adverse drug reactions (ADRs), mainly caused by drug–drug interactions (DDIs), occur in neurological wards and few data are available about incidence and prevalence of DDIs in this context. This study investigated—(1) the prevalence of drug–drug and drug–disease interactions in patients admitted to a neurological unit in Italy, (2) the risk factors for DDIs, and (3) the diseases and the drug classes mostly involved in drug–drug and drug–disease interactions. Methods: For 2 months, we performed a retrospective, observational study in the neurological unit of St Bassiano Hospital, enrolling 79 patients who received a drug prescription at discharge. Results: About half of the patients were discharged with 5 or more prescribed drugs, and 72% of patients showed potential, clinically relevant DDIs. Linear correlations were observed between age and number of prescribed drugs (P < .01) and between age and number of interactions (P < .01). The number of prescribed drugs was associated with the number of detected DDIs (P < .01). The application of drug interaction alerts and the use of medication inappropriateness criteria (ie, Beers criteria) were not satisfactory in choosing the best therapy for each patient. Therefore, multidisciplinary discussions of each clinical case was required. Conclusion: The study demonstrated that the neurological patient, especially if elderly, has a high risk of DDI and ADRs and that many of these can be avoided by case discussion in multidisciplinary team meetings, in which the presence of a dedicated clinical pharmacist is crucial.