Potentially inappropriate drug treatment among older people with cognitive impairment

Abstract: Background: The aging process contributes to alterations in organ systems, which lead to an increased risk for chronic conditions. Drug treatment is an important strategy in the management of chronic conditions; however, pharmacokinetic and pharmacodynamic alterations contribute to increased sensitivity to drug effects. This sensitivity is even more pronounced among older people with major neurocognitive disorder. Nevertheless, this group of people is often exposed to potentially inappropriate drug treatment associated with serious adverse drug reactions.Aim: To identify patterns of potentially inappropriate drug treatment and factors associated with this type of drug treatment among older people with cognitive impairment to enable further improvement of drug treatment and diminish the risk of adverse drug reactions among this vulnerable group of people.Method: Explicit criteria were utilized to identify inappropriate prescriptions based on renal function, potentially inappropriate medications according to age and clinically relevant drug-drug interactions among older people with cognitive impairment admitted to two hospitals in Northern Sweden. The first two studies included 428 people and the third study 458 people. Medical records were used as the data source. Moreover, explicit criteria were used to identify potentially inappropriate medications according to age among 1,881 and 1,305 nursing home residents in Västerbotten county in 2007 and 2013, respectively. The association between the length of nursing home stay and the use of potentially inappropriate medications were investigated based on information in questionnaires. Finally, the use of potentially inappropriate medications according to age were investigated three years pre- and post-diagnosis of major neurocognitive disorder among 67,226 older people registered in the Swedish registry for cognitive/dementia disorders.Results: Every tenth of the people admitted to hospital had at least one inappropriate prescription based on their estimated renal function. Moreover, 40.9% had at least one potentially inappropriate medication and 43.2% had at least one clinically relevant drug-drug interaction. Pharmacodynamic interactions were found to be the most common type. Increasing number of prescribed medications was significantly associated with having at least one potentially inappropriate medication according tovage and at least one clinically relevant drug-drug interaction, respectively. Moreover, potentially inappropriate medications were common among nursing home residents but had decreased 2013 compared to 2007 and were only to a lesser extent associated with the length of stay. In the nationwide study population, it was found that potentially inappropriate medications according to age were overall low and decreased continuously three years pre-diagnosis until three years post-diagnosis of major neurocognitive disorder. Consequently, the use of potentially inappropriate medications was found to be significantly lower post- diagnosis except when concerning antipsychotic drug treatment, which was significantly higher post-diagnosis when compared with the pre- diagnosis period.Conclusion: Potentially inappropriate drug treatment is common among older people with cognitive impairment admitted to the hospitals in Västerbotten regardless of their type of living. Increasing number of medications was significantly associated with potentially inappropriate medications and clinically relevant drug-drug interactions. The decreasing trend of potentially inappropriate medications among nursing home residents and among older people with a major neurocognitive disorder is positive and indicates an increased awareness of potentially inappropriate drug treatment in healthcare.