Background: Explicit criteria for potentially inappropriate prescriptions in the elderly are recommended to avoid prescriptions of duplicate drug classes and to optimize monotherapy within a single drug class before a new agent is considered. Duplicate drug class prescription (or therapeutic duplicates) puts the patient at increased risk of adverse drug reactions with no additional therapeutic benefits. To our knowledge, the prevalence of elderly inpatients receiving therapeutic duplicates has never been studied.
Objectives: Our objective was to assess the prevalence of therapeutic duplicates at admission, discharge, and 3-month follow-up of hospitalized elderly patients.
Methods: This cross-sectional prospective study was conducted in 97 Italian internal medicine and geriatric wards. Therapeutic duplicates were defined as at least two drugs of the same therapeutic class prescribed simultaneously to a patient. A patient's drug therapy at admission relates to prescriptions from general practitioners, whereas prescriptions at discharge are those from hospital internists or geriatricians.
Results: The study sample comprised 5821 admitted and 4983 discharged patients. In all, 143 therapeutic duplicates were found at admission and 170 at discharge. The prevalence of patients exposed to at least one therapeutic duplicate rose significantly from hospital admission (2.5 %) to discharge (3.4 %; p = 0.0032). Psychotropic drugs and drugs for peptic ulcer or gastroesophageal reflux disease were the most frequently involved. A total of 86.8 % of patients discharged with at least one therapeutic duplicate were still receiving them at 3-month follow-up.
Conclusions: Hospitalization and drugs prescribed by internists and geriatricians are both factors associated with a small but definite increase in overall therapeutic duplicates in elderly patients admitted to internal medicine and geriatric wards. More attention should be paid to the indications for each drug prescribed, because therapeutic duplicates are not supported by evidence and increase both the risk of adverse drug reactions and costs. Identification of unnecessary therapeutic duplicates is essential for the optimization of polypharmacy.